I spent all weekend migrating my current project over to Studio One, learning how to setup Studio One and starting mixing in Studio One.  The process appeared very painful at first, with some roadblocks along the way to which I had to find workarounds.  I was very skeptical in that I knew that I am going to throw away 30 years of experience and knowledge on how SONAR works but realize that the time to go through this painful process is now.
 
I will say that at first my mind was telling me I was right in that nothing could replace Sonar or that it would take months to be able to put a project together in another DAW (learning curve).  I was wrong, once I got to know my way around a bit, it became easier and more enjoyable.
 
My project includes about 5 instruments triggered with MIDI.  Using Kontakt, BFD3 for drums and UVI. I also have live guitar and bass tracks along with live vocals (wave files).
 
I was able to save my Sonar project as a MIDI format 2 file and simply load it into Studio One.  This method copied along the tempo map from Sonar as well.  I then had to delete all the blank audio tracks that came with the MIDI file from Sonar (trying to load my audio into these tracks caused Studio One to crash).  I will also say that I was using Studio One 2 in the beginning and that may have been the problem (not the latest version with its bug fixes).  I was then able to load in all the wave files from the project directly from the SONAR audio folder of the project.
 
I also wanted to record some live track stuff so I redid the bass guitar directly in Studio One.
 
Now, the good news.  Studio One is so much more responsive than SONAR (probably because its genesis was a few years ago and not decades ago, no legacy code).  Also, the music sounds better in Studio One than it did in Sonar.  It is the exact same VSTi's, MIDI tracks and audio tracks, all mixed using the same plugins that were used in SONAR.  I did not use any native Studio One plugins.  I have no idea why this is.  A real good example of how responsive Studio One is compared to Sonar was obvious to me as soon as I imported a wave audio file into an audio track.  This would take 15 to 20 seconds in SONAR and it took less than 1 second in Studio One. Also, the project in SONAR was using about 25 - 30% CPU but in S1 it was only using 15-16%.
 
The GUI is quite different and I will miss the track ICONS from Sonar.  My eyesight isn't that good and the instrument track ICONs were a god send in Sonar.  The routing is different too; the options are all there but if you insert an FX bus, you can't do a send from the FX bus to any other bus.  Let's say you add an FX bus for a delay.  You insert the delay but you have NO send mechanism to sent the output of the delay to the reverb bus.  There are work arounds to this but just wanted to explain how the routing is different in S1 than SPLAT.  But, the bottom line is that I was able to do what I wanted re creating the mix.  Editing tempo maps is a bit different.  S1 has the same tight integration with Melodyne as does Splat, so nothing loss in the ARA department either.  For education purposes, I tried to load a SONAR plugin(Breverb) into S1 but it wouldn't let me with a message that Breverb can only run within Sonar.  No biggie for me in that I don't use any Cake plugins other than Channel Tools but I am sure that S1 has a replacement tool.
 
Bottom line, if you are thinking about Studio One and you are a long time user of SONAR, don't worry, after a few hours of project time in S1, I actually like S1 better than Sonar (time will tell but that is my current thoughts after one weekend with S1.  I think that S1 is 50% off until tomorrow, 11/27 as part of their Black Friday sale.
 
I already owned an earlier version of S1 and was able to upgrade to the latest (FULL) version for $99.50 directly from Prosonus web site.
 
Good luck to you all in finding a new DAW for your projects.  I am still very disappointed and sad over the SONAR shuttering news but hey, life goes on.  
 
I also want to thank all the kind folks on this forum who have helped me and others over the years.

Just use the 'normal' buss's and forget the FX buss's. Then it's the same as you are use to.

Yep I have also spent all weekend learning Studio One and I absolutely love it. I'm a 25 year sonar user. For my projects the workflow is so much quicker than sonar that I'm saving tons of time. I'm looking at the whole sonar fiasco as a blessing in disguise.

kapelle
Yep I have also spent all weekend learning Studio One and I absolutely love it. I'm a 25 year sonar user. For my projects the workflow is so much quicker than sonar that I'm saving tons of time. I'm looking at the whole sonar fiasco as a blessing in disguise.

 
You can add me to the list of converts. I find myself in exactly the same position. I have used Cakewalk/Sonar for 25 years. Having spent 2 days developing a workflow to transfering 165 projects, I am hugely impressed with Studio One. Solid and fast.  Once its midi editing catches up it will be unstoppable:)

I have converted to Studio One. At first I thought that I was going to miss Sonar, but I haven't due to the fact that I  am having a lot of fun creating, and writing in Studio One. I think that there are some similarities in the two DAWS, but Studio One's workflow is a lot easier and fun. Studio One seems to focus more on the modern ways of making music. The note FX feature is great and can really help with the creative process. Studio One also has it's own CLA compressor. No need to get one from Waves or UA. I am very satisfied with Studio One so far!

I am considering another DAW and your comments about Studio One have me leaning toward it.  I use a lot of audio loops and input guitar tracks myself, but about 40% of my tracks are MIDI, typically synth and bass tracks.  Does Studio One have a piano roll view for MIDI input?  I find it my preferred method.  Do you know if Studio One allows use of Rapture/Dimension and V3ta+, or are these Sonar exclusive?   Thanks for any feedback on this.

Yes, S1 has a piano view for MIDI editing... it isn't as robust as SPLAT but it surfices.  I haven't done to much editing but it is there. Hurry, if you are going to pull the trigger and save 50%.  Sale ends today, 11/27.
 

MarkSSwanson
I am considering another DAW and your comments about Studio One have me leaning toward it.  I use a lot of audio loops and input guitar tracks myself, but about 40% of my tracks are MIDI, typically synth and bass tracks.  Does Studio One have a piano roll view for MIDI input?  I find it my preferred method.  Do you know if Studio One allows use of Rapture/Dimension and V3ta+, or are these Sonar exclusive?   Thanks for any feedback on this.

Yes, Yes, Yes and Yes, and no they are not SONAR exclusive

can anyone compare mixcraft 8 with studio 1
thank guys

I spent a bunch of the weekend with SO3.  I often struggled to find how to do something (render Melodyne edits for example), but nearly always eventually found it.  
 
I miss docking plugins in skylight.  I miss the event editor too.  
 
By comparison, if I wanted to use Addictive Drums 2, all i had to do was pull the plugin into the main window, click on separate outs on AD2, then go to the mix window.  I could click on the plugin name and it would give me the option of creating individual channels for kick, snare, hats... with the tracks already named.  That is so much more efficient than having to set the tracks up manually, tho saving a template gets around it the second time.  
 
I am anxious to try this with my own drum patterns.  I use a zendrum to put the beats in and usually do (1)kick/snare, (2)hats, (3)cymbals, (4)toms...In sonar, the 1-2-3-4 showed up as separate clips.  that means that if I came back to it later and wanted a different syncopation on the hats for example, i only had to mute the hat clips and retrack.  Not sure on SO3.  Will keep you posted.