I have installed X2 a couple of days ago and opened the old x1 projects without problems working some hours without negative but only positive surprises at the moment. Whit X1d there was still a lot of bug and issues that i used to face almost during every session (crash, hang of the system, freeze and so on).
I hope this positive feedback will continue, i think Sonar is absolutely the best DAW in term of workflows and overall functionalities but with some important insane instability. If the first impression is not wrong, it will be n. 1 without any dubt.
my 2 cents
Vincent