The percussion may have reverb, but it doesn't have enough reverb. Compared to everything else, it sounds like you put the drums inside of a tube made of sound absorbing foam.
There's a difference between samples and how you use them. You need to tweak samples and humanize them, which is much easier a software interface rather than on a keyboard screen interface, because not all instruments have the same humanization techniques as a piano.
Some would argue that humanization is easier on a keyboard, and they're right in most points of view. However, there's not nearly as much control for instrument tweaking AS ON A software library.
What I'm saying is, if I wanted more control, I would buy EWQLSO rather than a keyboard. If you already have a keyboard, I'd recommend buying EWQLSO and channeling through software using your keyboard as a MIDI controller. Lots of room for tweaking the instruments, and if you have the MIDI you can also edit the MIDI in a DAW/Tracker (like Fruityloops, Reason, or Logic) to fix some of the timing issues you may have in the future. (Missed a snare hit by a half step? No problem, go into the MIDI and move the snare hit back a half step)