VST 3.0??????????
That's pretty old. Can you get it for free?
That being said, I use both Cubase (3.6 and 5.0) and Cakewalk (Pro Audio 8) and prefer Cubase for the user interface. However, Cakewalk is a bit better for MIDI editing.
I've demoed Sonar and it hasn't won me over. Also, Cubase SX is supposed to be pretty good.
All IMHO and YMMV,
Matt