Hey Strummer,
I had an 828mkII & Logic for about 4 years before converting to a 003 and PT to better handle tracking full sessions.
The 828 preamps were not particularly noisy unless they were completely dimed. With a condenser mic they should be "quiet". The line inputs were fine, same thing. We're not taking whisper quiet but definitely usable and not obviously fucked up.
A couple of things to watch out for:
+ at least in the mkII, there was a +6dB digital boost that could be applied to the inputs. Maybe if that is engaged it could bring out the noise floor unacceptably?
+ There were minor QC issues with my mkII. I had a backlight go out (no big deal) and then the FW controller chip died (big deal). MOTU service was good and they only charged me for shipping even though the unit was waaaay out of warranty.
I wouldn't call the 828 notorious for noise. Look for configuration issues first, then for inter-channel discrepancies. If you find the noise to be disgusting then it's probably a real QC issue... especially if it's with the line inputs. They were always acceptably quiet in my experience.
There are a ton of these units around. If you can get your hand on a second unit of the same model, an A/B test would be very effective.