Hi -
I've been using Dremel tools for about thirty years now, and can't imagine building models without them (or something similar). Some of my friends disagree vociferously, but when newcomers to the hobby ask me what their first major tool acquisition should be, I always suggest a Dremel tool (or something similar).
I have, however, always had one complaint about Dremel Moto-Tools. Whenever Dremel brings out a new product, the advertising emphasizes how fast and powerful it is compared to the last one. To the model builder, both those attributes are just about irrelevant - except that to anybody working with plastic, slower is better.
My first Dremel tool was a 1975-vintage single-speed one, which I promptly discovered was too fast for any civilized modeling purpose. So I bought a hand-operated speed control for it. With that contraption I could dial in a speed of zero, put a stationary drill bit down exactly where I wanted it on the workpiece, and, by turning the dial, gradually ramp up the speed till it was just what I wanted. That, to my notion, is the way to use such a tool.
Unfortunately the company seems to have quit making single-speed Moto-Tools. The dial-operated speed control also seems to have bitten the dust (though I believe the foot-operated one is still available). The current built-in speed controls are nice and handy, but they don't go down to zero. (If I remember right, the slowest speed on most of the newer models is 5000 rpm. That's just about slow enough to drill a clean hole in a piece of styrene IF the drill bit is nice and sharp. But a slightly dull bit will produce a gooey mess. I speak from experience.)
My current favorite Dremel equivalent for most model-related jobs is one that I got from Woodcraft. (That, incidentally, is a fine source of tools and materials, geared mainly toward woodworkers but incorporating all sorts of stuff that's useful for modelers as well. The website is <www.woodcraft.com>.) The manufacturer is a German firm called We-Cheer, and the tool is about a third as big and heavy as the smallest corded Dremel. It has only one speed (too fast), but works great when I plug it into the good ol' Dremel speed control. Dremel chucks work perfectly in it. It feels almost like a pencil in the hand, has a lightweight cord that comes out the back end, and costs something in the neighborhood of $25.00. I still keep my fairly modern, variable-speed Dremel on the workbench for heavy-duty work (e.g., in the router attachment), and I like my Dremel Mini-Mite for all sorts of stuff, but I recommend the We-Cheer for general modeling purposes.