I have a Randall RM100 (which is what I think you mean - the modular amp), and it totally kicks ass. There are other great amps in the price range, like noodle says, but I love the RM. Some modules are better than others (although it's all down to taste), but the best of them are as good as any preamp I've ever heard, and I think there is something for all tastes (even tele players :lol:). Personally, I like the balance that the RM strikes between versatility and simplicity, without losing focus on sheer good tone.
When I was making my decision I was looking at a Randall T2, which is the best sounding rock amp I've heard, and uber-simple, and a Vetta, which we all know is the king of versatility (for better or worse), and I decided to go somewhere in the middle. I think I got the best of both worlds :D