Personally, I can't really comment on either, but will suggest you have a look at Photo Mechanic 5 from Camera Bits.
It's super fast to ingest, catalogue, key word, rate, colour code, etc... It literally takes me a few minutes to ingest and sort through several hundred shots, giving them a rating, key words and colour code.
I find that the initial cull is the hardest part of the entire post production process, so to do this so quickly whittles me down to the real possibles very efficiently. Then I can rate those further and with a bit more time to do so, before stepping on to the editing.
I forgot to mention, it's only $150 and you can have it loaded on 3 machines. I have it on my MacBook Pro and iMac, so I can ingest while I'm out and about to see things on a nice 15" screen, instead of chimping all day long!
I'd say that Bridge is a poor DAM application at this point. I think LightRoom and Aperture have the most bang for your buck. Given the lack of meaningful updates on Aperture, indicates that LR would be a better fit.
I'm not familiar with Media Pro at this point. I used to use iView Media Pro, then MS bought the application. By then I think Aperture and LR hit the streets with superior features. I'm not sure how it measures up against those guys now. It could be a great product I'm just not familiar with it.