I have Battery too, it's a great program, very flexible and it works in nicely with Cubase too. If you are looking to create realistic drums for rock/metal check out Drummer From Hell Superior (by Toontrack). It's a VST plug-in that pulls real drum (a large variety for each drum to keep realism) off your hard drive. You can also bleed sound across mics for a more realistic sound plus you get a number of different kits to play with. Add all of that together, then look at www.groovemonkey.com
, they just came up with a cd of pre=programmed midi files for use with DFH Superior... a very tough job made easy!
Also, you keep everything in a digital environment, that means you can do just about anything with the sound with a few clicks and it's all reversable. Personaly, I wouldnt bother with a drum machine.