I'm a long time Cakewalk/SONAR user and have used just about every version along the way to X2a.  I just finished a song a month or so ago using X1d and have stayed away from X2a until I was finished with the project I started in X1d. 
 
So, I've been using X2a for the new song for about a month now and...I really like it.  My experience with it has been pretty darn good.  Yes, I do get the odd crash now and then...maybe twice in the last month but overall it's been pretty solid for me.  I also had a stange MIDI issue where the MIDI was there but seemed to be muted ... I chalk that one up to lack of any real MIDI knowledge on my part.
 
I'm not generally a fanboy.  In fact I've done my share of complaining right here from time to time.  But, again, I'm dig'n this version...X2a.

Good to hear man.  Going well here also.

Good news!!!
 
best regards,
mike

I should clarify that I have some of the same grips that I see on this site from a large number of participants.  I'd like to see more color options, a better implementation of track lanes and, of course, we all want it to be as stable as possible.

I likes me X2a too.
 
Fortunately for me, most crashes I get are Operator Error.
 
I chalk my positive experience up to the fact that since I went full 64bit I use very little 32bit plugs anymore. 
 

Colors and track lane enhancements... count me in.   Yet X2a is still my favorite version yet.
 
Funny though, I've been using a handful of 32bit plugins all along  - synths and FX - and haven't had any issues.  I guess BitBridge likes me.  The only one that did cause some grief was a freebie called "Orca", so I just don't use it (nor need it).  
 

I'm still using a couple of 32 bit plugs, too, although I try to stay 64 bit.  The only issues I've had have been using any 32 bit synths in Simple Instrument Tracks - occasionally I get some weird behaviour then..

I don't know what to say about the 32 vs 64 bit conversation.  I've been running 64bit since I got the this box from Purrrfect Audio (StudioCat) and, as I mentioned, I have a SONAR crash once or twice a month...sometimes less.  My crashes usually happen when I've been sampling soft synths to determine which one I want to use.  I usually go through a bunch of them pretty quickly and that's when SONAR seems to choke...again, not very often. 

I can honestly say that I can't remember when Sonar last crashed for me.

When I first installed X2 it crashed fairly often, but since the "a" update it has only crashed a couple of times, but not for months now.

I have seen the choking behaviour when you preview lots of soft synths, but again not for a while.