Recently I’ve started to use Ultrabeat from Logic Pro as the main drum machine system for minimalist/techno productions.
It takes a while to figure out the UI, but this quicktime movie at the Apple web site would help someone getting started with this drum machine (assuming you have Logic Pro, of course).
The reason I like Ultrabeat, and I have many other drum systems available, each having their good points, is that in addition of simulating the TR808/909 sound that is needed for a lot of this modern electro/minimalism techno movement we have just now, you could tweak the sounds further quite a lot.
In addition, it has random pattern generation that I like using from time to time, as well as envelopes tied to the pattern, so I could make for example the drum kicks sound differently depending on the bar position.
It also has a recording mode, I could build a set of patterns, and record the order while hitting the keyboard and the track is playing.
I’ve read about problems related to adding your own drum loops, the UI is not that easy to grasp. For me, it’s not that often I add in drum loops — I start from an existing set or using the synthetic ones, and then modify them further so they sound fresh.
But what I often do is to have multiple Ultrabeats running, one with just the kick, and others with just the snare, then one with hihats, and one with percussions, and so on. By separating these elements I could run different kinds of compressors on each one of them, or adjust the balance from the UI, instead of tweaking stuff inside Ultrabeat itself.