I had no trouble with the install. I'm running Windows 7 Home Premium 64-bit and installed only the 64-bit version of X2 Producer. One thing that's on my wish list is an actual upgrade type of installation so you don't end up with these dual installation situations. I remember having an issue between Sonar 8.5 and X1. Tech support told me how to fully uninstall 8.5 which included going into the dreaded Registry.
FIRST CRASH REPORT
I opened an X1 Producer Expanded Edition (latest update whatever that was) project in X2 Producer, added Rapture 1.22 (which I already had from a prior purchase so did not install the version that came with X2), played it for a few seconds and watched in shock and awe as X2 crashed.
The Problem Reporter did not come up and I had to do a restart to get my ASIO driver back for my Roland Quad-Capture soundcard. I reported this manually as a problem and also e-mailed tech support.
SECOND CRASH REPORT
I created a new project in X2, added Tone2's ElectraX (64-bit), played a bit, that worked, then added Tone2's Gladiator (64-bit) and X2 crashed while trying to load the synth. The Problem Reporter came up, however, my ASIO driver was not released, so another restart.
One thing I noticed with both crashes is that the Sonar EXE did not show up in the Task Manager. I have Sysinternals' Process Explorer but it's never been able to kill the Sonar EXE process after a crash.
My overall impression is that X2 Producer is flakey and there will definitely be a patch within the month based on the problems I'm reading about on the forum.