I recently upgraded to a windows 8 laptop with an i7 processor.  I was a little reluctant - having heard horror stories all around about sonar, my audio interface and my controllers. 
The good news:

Sonar X2 is working flawlessly.  I've only had one whitescreen in the last 3 weeks.  I have an m-audio fast track ultra, and that was my main concern, as they do not have a win 8 qualified driver yet.  (what good is a new computer if an audio interface is not compatible, right?)  No problems there either....  It works on the usb 2 bus, on the usb 3 buses, and on a bus-powered usb 2 hub plugged into the usb 2 ports and usb 3 ports.  

I've been doing a lot of testing, notably a project with 65 audio tracks and all pro channel modules enabled and multiple fxchains loaded into the pcs.  I've been setting up pure data to run significant amounts of midi data into sonar using about 8 instances each of massive, kontakt, dimension, rapture and sound center and pentagon I.  Pentagon I with (esp the nothing patch) works with all the valley simulators, though I'm still showing 99+db spikes in the system which i take care of by having a pentagon track template with boost11 limiter loaded into an fx bin.  

I really can't say enough.  I'm about halfway through installing all my vsts and getting my system where it was, so I'll post more as I go along.  

I think with all the horror stories in the forum early on (and most people post when there are problems, right???) I thought I'd post some good news.  I'm a pretty happy camper and am looking forward to more musical armageddon to come!  If you're thinking about upgrading your system I can say there are probably more good stories out there than bad, but the bad is all we usually see.

Cheers everybody!

+1 CW

That is good to hear. Thank you for posting.

That is good news-always nice to hear. I also am having great results with my new win 8 pro i7 laptop.
Seems faster than my desktop and runs Sonar X2a as you have stated-nicely.
 
Cool!

Thanks for that Swamp, and I'm glad it;s working out ok for you.

I too had a lengthy session on Friday/Saturday last, which included audio recording, V-Vocal editing, layer comping, extensive automation, copy/pasting of tracks & clips, inserting Fx chains, inserting soft synths, creating & editing Midi data and I didn't get a single glitch, let alone a crash.

I was control + s-ing like a madman (in addition to having autosave switched on) but it wasn't necessary.

This is getting close to perfection

Swamptooth - appreciate this post. Great to know Sonar X2 is working really well. Did you see some advantages to moving to Win 8? I don't have a touch screen so I'm baffled to understand the positives of Win 8 over Win 7. It looks like a confusing OS.

I concur with running Windows 8 as an OS for software apps.  I'm pretty happy with the stability of X2a on Windows 8 and everything about this setup seems more 'snappy and responsive'.

I'm not a big fan of the metro/modern interface on a desktop PC, and I find the experience of (having to) jump between that and the old desktop view for various PC settings quite jarring and unnatural.

But for purely running X2a on Windows 8, I think it's the best overall experience.  Even without getting into the touch support side of things.  Just be sure that your sound card is supported and I don't think you'll be disappointed.

+1 on the W8 experiece here as well.  Early days, and I would highlight the importance of securing W8 drivers wherever possible.

I pinned the X2 launch to the metro/modern UI to save the click to the desktop.  I think you can default the launch to the desktop anyway.

My trouble at the moment is I'm spending too much time fiddling about with W8, syncing accounts and setting up the skydrive to actually do anything in Sonar!

I upgraded to Windows 8 a couple months ago and have not had any issues with X2. My perception is that X2 works better in Windows 8 than in 7.

I never thought it would be any different to windows 7 but I simply have not had a crash since doing the basic update to 8pro a couple of weeks ago. 7 would randomly crash about once a week. 
Performance wise I don't notice any difference, and use the traditional desktop., but stability wise I have noticed a difference.  
I7, x2a and win 8 does seem to have a high proportion of happy customers.

Win 7 stable and fast for me. Any issues I've had are clearly Sonar related or driver related.

Still for DAW purposes Win8 I'm sure is every bit as good as Win7. I have it installed as an experiment but won't use it for full on band recording until the first service pack comes out, or for a year, or if I get drunk and decide what I decided earlier was not the best decision. Whatever is first.