I'm using a new i7 laptop, along with a Roland QUAD-CAPTURE audio interface. The i7 laptop is pretty much Intel throughout, which is what is recommended. I've been watching all the topics here regarding the instability with X1, and I have to agree that, X1, is indeed unstable, compared to the other versions I have used (an unfair comparison, I admit, because I was using different plug-ins back then, and it was on a different system).
Having said that, and here's the rub, it is virtually impossible to determine what is causing Sonar to crash so much. It could be my hardware, or my software, or the operating system setup. But what ever it is, I too find that it can take quite a while for the Sonar executable to truly close down, and it is sometimes quicker to shut down and start up again.
On the positive side, so far at least, non of my current projects have been corrupted by the crashes, so as long as I save regular, I'm willing to accept that Sonar will crash from time to time...