You WILL find life easier with whichever way you go, IF you make sure your connected devices have drivers for whatever OS you seek to use.
 
Just a suggestion, 
 
Bob Bone
 

Mesh
 
I noticed in your sig that you also have a UAD1e....do you have any issues with the 64bit drivers or plugins?
I'm also building a new Win 8 x64 machine and will migrate from the Vista x32.

Nope - I haven't had any challenges at all. I do plan on eventually upgrading to the current UAD 64-bit offerings, and hopefully that goes smoothly. But no, I've had no issues whatsoever running the 32-bit UAD efx with X2a. In fact, these are the only exclusively 32-bit efx I've installed on my machine.

Runs better on Windows 8.
The only problem I found is if you have any firewire devices. Won't work - no legacy drivers. I have Liquid Mix16 sitting doing nothing now. Looks nice!

My take is that, while SONAR X2a runs great on Win7, it arguably runs even better on Win8 and I prefer Win8 in general (startup time, copy process, apps when needed, etc).
 
As others have said though it goes beyond SONAR. You'll need to make sure your other devices are happy with Win8 also, which is likely, but good to double-check.

Hey everyone, thanks for all the responses, definitely sounds like Windows 8 would be the way to go. The only hardware I have at the moment is my interface (Alesis IO2 express, which just uses ASIO drivers) and my Akai mini keyboard, which for basic use is plug-in play (I don't even use the software it has with it).
 
As far as SSD's go, fast load time sounds nice, but might not be enough to spend the extra cash. Are there general performance benefits since everything is retrieved so much faster, or is it pretty similar when you're actually working?

Please note that since you posted your audio interface's name, I looked it up to see about drivers for it for Windows 8.
 
Your audio interface provides a bit of code called ASIO4ALL - which is freeware that provides SOFTWARE ASIO driver processing.
 
Here is the Alesis link for your audio interface: http://www.alesis.com/io2express, and if you look at the downloads tab on that page, you will see the optional ASIO4ALL drivers listed there.
 
Whether on Windows 7, or Windows 8, you may find issues with your system handling the audio processing requirements of Sonar.  PLEASE NOTE that I am NOT telling you that you will have issues - just keep in the back of your mind that you MAY experience audio dropout issues using ASIO4ALL.
 
On the other hand, ASIO4ALL has worked for others in the past too, you can certainly start with it and see what happens.
 
I just wanted to make sure you understand that there is a potential for issues when streaming audio through ASIO4ALL.
 
IF you DO have issues with it, you can try using WDM, which is the native Windows audio driver, and if THAT does not meet your needs, you may have to look at replacing your audio interface with a more robust one.  If that DOES end up to be the case, then you WILL want to pick one that indeed does have ASIO drivers for Windows 8, and some of the older, less expensive audio interfaces do NOT have Windows 8 ASIO drivers.
 
I am not trying to scare you - just alerting you to a potential for issues, and what you may end up having to do to resolve them, should they become realized.
 
Bob Bone
 

ZeroContrast
 my Akai mini keyboard, which for basic use is plug-in play (I don't even use the software it has with it).
 

If it's a LPK 25 it should be fine.  I have one as an extra keyboard mainly for triggering keyswitches. I just connected it and it works. I have not had any issues with the programming software that came with it either.

@Robert, thanks for the heads up, yeah the ASIO4ALL driver is the one I use currently, I have found that it's not always the greatest, I used to have an Alesis Multimix (well still do but it's back in the US) that had it's own drivers, much better.
 
@Glyn, thanks for the info, that's good news. Mine's the MPK mini, which you probably know is the same thing just with the pads and triggers up top. So I should be good

http://en.wikipedia.org/wiki/Windows_Driver_Foundation
 
In the above wiki, you can see that the version of Windows Driver Foundation 1.11 has been available since Vista. For more than 7 years, it has been possible to develop drivers that will work on Windows 8, but it does not mean that all drivers that work on Vista or Windows 7 will work on Windows 8. For example, Vista supported versions 1.5-1.9 which are not supported on Windows 8. Windows 7 supported version 1.9 which is not available on Windows 8.
 
This means that it would be possible to have a driver that worked on Windows 7 that DOES NOT WORK on Windows 8.
 
I would expect most driver manufacturers to have been aiming their development for the most long lasting version of WDF, and consequently could have begun development on drivers that will work on Windows 8 since before Nov 8, 2006 when Vista was released.
 
For this reason, it is likely that your drivers for Windows 7 or even Vista WILL WORK on Windows 8.

There always going to keep us upgrading....I am running it on XP with no problems, once I got everything tuned in just right. X2 is stable, it is in my opinion, one thing leads to another that causes problems, this isn't written for that etc....I can not compare win 7 to 8? But I am sure 9 isn't far from being released either. I believe the graphics card, and multiple sound cards, as time goes on, starts causing most of the problems, then you go an update a drive thatdoesn't relate to this or that. It is all designed, so that we constantly have to spend money. And guess what? The general public is their salesman, go figure, right?