Feature:
You can adjust where the accents go, as well as the subdivision of each beat. It has tap tempo and even a tuner which will play all 12 pitches; you can adjust the reference tone (440 is the default, of course). There's a volume control which comes in handy, as well as a headphone jack.

Desirability:
I like the digital metronome arm and overall aesthetics, as well as the compact size.

Sound:
Pleasant to listen to for long periods of time.

Ease of Use:
Spend 5 minutes with it, and you'll figure it out. Pretty straightforward. More features than a typical metronome, maybe, but not hard to figure out how to do everything you want.

Overall:
I'd say this metronome is where it's at for most people. It does more than just click at a given BPM, having accents and subdivisions such as eighths, sixteenths, triplets, clave patterns, and more. You could go with one of the more elaborate DB models if you are looking for actual beats instead of just a click (I'm not familiar with these models). But for most people, I would venture that you will be satisfied with the features on the DB-30.

Feature:
Just right for most music students. If there were many more features, it would be more complicated.

Quality:
Seems to be well put together, and is easy on batteries.

Value:
It's a good value for any music student.

Sound:
The tone is pleasant enough, but easily cuts through a piano sound.

Ease of Use:
Five minutes with the instruction sheet, and you'll be able to dial up any rhythm you'll need.

Overall:
I'll use this as long as it lasts.