I have the Hart Dynamics StudioBX kit (very similar to
the Alesis DMPro, since the trigger pads are actually OEM'ed for Alesis by Hart), and I use it with
the Roland TD10 (+TDW-1 Expander) and
an Alesis DM5 as the sound modules. They are both very good, and I really like the Hart/Alesis trigger pads a great deal better than the Roland pads (which are significantly more fragile, in my opinion).
I played the previous generation of Roland E-drums (the TD-7s) with the rubber pads, and loathed them- and broke a lot of pads. The only thing that saved E-drumming for me was the advent of the mesh head pads, and the Hart cymbal triggers. The crashes and splashes are spring mounted on Aquarian mounts, and move as you strike them, so that you can "play through" the bow of the cymbal (and yes, chokeable versions are available!). I never could get used to hitting a crash cymbal that felt like a rock.
All of the E-drum modules these days can be tuned to provide a remarkably fine sense of dynamics: the trigger parameters are very widely variable, and with some care you can make them very nearly as responsive as an acoustic drum for dynamics, rapid retriggers such as scratch rolls, and so on. It is possible to avoid the "machinegun" trigger quantization problems, with a little care. The downside is that these units generally come with a "one-size-fits-all" trigger setup (or a totally screwed up setup, if they are a music store floor demo...). This means that your initial e-drumming outing will probably be disappointing: it takes time to really dial them in to fit _your_ individual style and technique, just like it takes time to position a microphone to get a good snare sound. However, once you do, you have a very viable instrument.
If you do decide to get a kit with the TD10 (like the V-Pro), I highly recommend springing for the TDW-1 also: it has much improved sounds, especially for the cymbals and kick, and it makes the trigger hardware much, *much* easier to tune...
One other important resource for V-Drum info:
http://www.vdrums.com
I've been posting over there under a different name for a couple of years now, and there is a lot of setup and technical info available there.
Bottom line for me? E-drums will never replace my acoustics, but having said that: my acoustics haven't been out of their cases since I bought the e-kit.
Better yet, the cops haven't shown up on a noise complaint since I bought it, either! (;-)