There have been some system-specific issues, one of which ended up being a bad motherboard, but the general consensus of what I have observed in the forum is that the X3d release has been one of, if not THE, best releases in a long long time.
Even the system-specific issues were largely resolved, to the best of my knowledge, and were things like out of date C++ components from not running Windows Update, or not using Run As Administrator, or forgetting to suspend antivirus software while installing Sonar.
Yes, there are some bugs, and some features that folks hope get some attention moving forward, but most folks seem quite happy and productive with X3d, which you can see with both tone and substance with forum threads.
X3d has some really really nice features - nothing to be afraid of. On top of the software, the folks here in the forum have been VERY good at helping folks who have trouble getting things going, and are a SOLID asset. Cakewalk itself has also been extremely helpful in their maintenance approach with X3 - with 4 maintenance updates released so far, and at LEAST one additional one coming at some point.
For stability, features, peer assistance, and aggressive maintenance, you really can't beat X3d.
GO FOR IT!!!! :)
Bob Bone