With Superior .... just a quick list ....in no order...but you get attack/decay adjustments on the drums...(and the tuning which EZD2 now has) and a bunch of built in FX in the mixer section...nothing special but nice. I think the biggest thing is the sound of the drums are better, imo and *if* you like "room sound"... you get piles of that, that you can add zero ...to as much as you want. IOW, if you want to do the Led Zep monster kit in the hallway, you can approximate, where in EZD, I'm not sure you could replicate. I think the MIDI grooves are a little more "tasty" overall. That's hard to explain, but maybe like a better drummer, but playing still contained... HH stuff and side stick seems a little more "adult" for a lack of words. Plus some extra mics, here and there, that you can blend to taste and the mixer...although waaaaay too many channels for the average use... now has busses and such that let you work inside the program, should you not want to do that in Sonar. Nice presets too from Toontrack, from the full kits, to individual drum, HH sounds, etc
However..IMO...if you like the sound of drums recorded in a nice big, wooden wall'd, famous studio... you'll love the NY vol 1,2 and now 3...which to me are a couple notches above the kits EZD has. Forget the reverb plugs...you won't need them unless you're doing something really wild.