Installed and now have a couple hours with X3. I am very pleased. Lots of new plug ins, I love the Prochannel EQ zoom !!!!  Several added controls scattered about, also really like the channel colors!!  I would think the the plugs were well worth the upgrade price alone. I haven't noticed any funtionality differrences yet.  All seems to be working great. I admit I was a bit worried due to the issues I experienced with X2 at first.  Well done Cakewalk!! :)