I use Sonar because it is my native language. I started with Cakewalk version I don't know what. And I'm pretty sure, though it is now several houses later, I still have a factory disc labelled Cakewalk Pro Audio somewhere in the basement. 
 
Over the years I have learned a lot of nuances of Protools and a few things about Cubase. Not because I used them, but because that's what my friends were using and if I wanted to hang around with them, I had to know how to use their tools. 
 
Oddly those friends have switched horses several times. First Protools, then Nuendo, then Cubase and now I think Studio One and Logic. All the while, I've been on some version of Cakewalk/Sonar. I've helped them through their various struggles as best I was able and learned their various platforms as needed to facilitate working with them. 

But I learned a long time ago to stop saying 'yeah I dunno, I use Sonar and I don't have any problem like that' because it always seems to fall on deaf ears and/or just seems to piss them off. I guess the problem is I'm the lone keyboard guy of the group and everyone else I know is a guitar guy. And their perception is that any serious DAW should be audio first and MIDI as an add-on but to them Sonar is a MIDI first and audio second solution. 

I've given up trying to argue that because as I've said, it falls on deaf ears, at least in my group. So I'm relegated to a world where I'm forced to learn everyone else's DAW if I want to work with them because none of them seem the least bit interested in learning mine even though I've never switched horses and my solution still works great after all these years. C'est la vie.

JohanSebatianGremlin
I use Sonar because it is my native language. I started with Cakewalk version I don't know what. And I'm pretty sure, though it is now several houses later, I still have a factory disc labelled Cakewalk Pro Audio somewhere in the basement. 
 
Over the years I have learned a lot of nuances of Protools and a few things about Cubase. Not because I used them, but because that's what my friends were using and if I wanted to hang around with them, I had to know how to use their tools. 
 
Oddly those friends have switched horses several times. First Protools, then Nuendo, then Cubase and now I think Studio One and Logic. All the while, I've been on some version of Cakewalk/Sonar. I've helped them through their various struggles as best I was able and learned their various platforms as needed to facilitate working with them. 

But I learned a long time ago to stop saying 'yeah I dunno, I use Sonar and I don't have any problem like that' because it always seems to fall on deaf ears and/or just seems to piss them off. I guess the problem is I'm the lone keyboard guy of the group and everyone else I know is a guitar guy. And their perception is that any serious DAW should be audio first and MIDI as an add-on but to them Sonar is a MIDI first and audio second solution. 

I've given up trying to argue that because as I've said, it falls on deaf ears, at least in my group. So I'm relegated to a world where I'm forced to learn everyone else's DAW if I want to work with them because none of them seem the least bit interested in learning mine even though I've never switched horses and my solution still works great after all these years. C'est la vie.

This is something I keep running into. I use Sonar professionally in my composing / sound design job at the biggest media house in Finland (the Finnish Broadcasting Company). And I've always wondered why people are so locked on the oh-this-is-the-only-software-professional-use mode. For me having a tool that I do not need to change between jobs is a relieve. No jumping between two or more software to do different things. I can just chug anything into a project I want. And still people tell me "all the professional use Logic", which can be so easily proved as BS.
 
What I always tell people is that it's not the software, it's what you do with it. The people listening to your productions aren't going to give a flying fudge whether you used a certain "professional" software or not. They care whether what you've made is good or not (and most of the time they just really won't care at all either way).
 
From my experience with different "pro" DAWs I can say that the one that has pro in the name (I'm looking at you BroTools) is the most clunckiest piece of gear ever deviced... I'd rather use Logic, which to my Sonar loving senses is completely illogic software... :D
 
End rant.

Kuusniemi
What I always tell people is that it's not the software, it's what you do with it. The people listening to your productions aren't going to give a flying fudge whether you used a certain "professional" software or not. They care whether what you've made is good or not (and most of the time they just really won't care at all either way).
 
From my experience with different "pro" DAWs I can say that the one that has pro in the name (I'm looking at you BroTools) is the most clunckiest piece of gear ever deviced... I'd rather use Logic, which to my Sonar loving senses is completely illogic software... :D
 

Well said. I don't understand how people get so attached to a piece of software that they go trolling around bashing alternatives ...
 
I use Sonar because it provides what I need - and it has become really stable and keeps expanding its functionality faster than I can find the need for the new stuff. Probably my mind is too limited to think of something that I'm truly missing there, either.
 
Apart from Sonar I bought Mixbus with the idea to become as cool as bapu. So far it has not worked ... well, Mixbus itself works, apparently that's not the issue here ...

Rob[atSound-Rehab]
Apart from Sonar I bought Mixbus with the idea to become as cool as bapu. So far it has not worked ... well, Mixbus itself works, apparently that's not the issue here ...

LOL!
 
You need the Alembic bass too.
 
DOH!

I'm a registered user of three DAWs...
 
Sonar Platinum is my main one for sequencing and recording, but I also have Reason 9.1 on both my studio PC and my MacBook Pro, mainly for composing and sequencing; I rarely use the audio track recording features of Reason.
 
I also have Studio One v3.3 on both computers, but mainly as a mobile recording DAW if I have to take my MacBook Pro somewhere outside my studio to record tracks. The tracks usually get transferred to a Sonar project in the end, though.
 
I'm mainly a PC Windows guy but I have a MacBook Pro because I've never met a PC laptop that I actually liked. Apple wins hands down in the laptop game.

I'm exactly in the same land  as Bapu here (Mix buss and S1 ) ... i will only add that sometime , the fact that i'm less confortable leads me in another creativ land , as we know limition is a key ....
 
Also in my case , i have to know pretty every daw for my job : teaching ... (so i have to master also Live , PT , Cubase ..ect )

one possible use case: after moving from one daw to another, one might keep the original daw as an archive-retrieving tool for accessing old projects
 
i have sonar, studio one, live and mixbus

Do Octamed and Digital Orchestrator Pro count? I still have those somewhere, including the Amiga for the Octamed. Haven't used DOPro since Windows XP, I think. I remember that Roger McGuinn was also a user of DOPro.

I have Sonar Platinum(recently upgraded from pro), Reason 7(still considering the 9 upgrade) and Reaper 5.
 
I bought Reaper with a plan to start using it instead of Sonar for a band that I collaborate with other people on as it is both pc and mac but could never get used to it.
 
Reason 7 I bought and use it to rewire as well as occasionally standalone. I don't really use it to record audio into but I do sometimes export a drum loop from Sonar turn it into a rx2 file as I like being able to hit tab in reason to turn the rack around and start plugging things in randomly just to see what happens.  I mostly write industrial rock/metal type stuff and the first daws I ever used were reason 2 and fruity loops 2. And while I don't miss fruity loops I did miss the whole workflow of Reason.
 

I've been using Cake since Pro8.  I went to Reaper during the X1/X2 era and moved back at X3.  There are things I like about both and things I wish worked differently in both - but I'm pretty much 98% with SONAR these days.
 
I also added Tracktion 4 mainly to help a collaborator that was already using Tracktion.  I recently upgraded it to version 5, but I only ever launch that to help my partner figure out how to do something.
 
I continue to keep Reaper up to date, but at license renewal time I may decide to leave it wherever it is.
 
It IS handy to have alternative DAWs to help troubleshoot VSTs, OS, hardware and such, but honestly SONAR has been pretty dang solid for me for a long time now.