'OlPal
I can't open any of the "legacy" IK stuff in X2.
By "legacy" I mean any of the VSTi's or VST's that haven't had a 64 bit update.
CSR, Ampeg SVX, and all the Synths; SampleTank, etc. Dead in the Water!
This is on my Win 7 x86 machine and my x64 StudioCat.
If I open an existing X1 project that includes any of the "Legacy" stuff I get this:

If I try to insert any of the "Legacy" stuff into an X2 project, Sonar crashes.
I tried uninstalling and re-installing SampleTank, but that didn't help.
I can't believe I'm the only one having issues.
Evidently when IK does the x64 update something in the x32 dll changes as well.
The new Tracks works great and gives me access to CSR.
Amplitude works great and has the SVX patches as well, so I'm good to go.
But all the VSTi's are dead; at least in X2.
Part of the "bad taste in my mouth" with X2 was the issues opening projects that included the IK "legacy" stuff.
Once I got that sorted, its down to the Lanes issues, and the random white screens.
Still not quite "Prime Time" (X2a I mean) on my machines at least.
I know some are tickled pink, and some had/have issues with X1.
Go figure...
YMMV
Tom