UD has been some of the best ROMs I've ever put on my Droid since I rooted in Feb. On 2.1, there was no question. On 2.2, there's been a lot of great choices, but UD had been overshadowing them.
For the better part of the month I've been using LFYv1.71 as it's simply the best ROM I've ever flashed. On my Droid (key terminology), it's the fastest and smoothest and has by far the best battery life. There's enough customizations that make it worth it.
Now, UD isn't exactly far behind. It's almost as fast, but I did experience occasional lag. Only CM can rival UD in customizations, and I think UD is better overall than CM. Battery life does take a bit of a hit, though, with so much going on in the ROM.
So the answer to your question is, yes, it really is that good. It may or may not be the most suitable ROM for your Droid and only trial and error will prove that to you. Most ROMs have a review in the OP so you can get a feel of real-world application, but I don't know if someone did the last UD.