I haven't been to 'Ohana since it switched to Stitch and Friends. That said, it was a much more pleasant and relaxing enviornment. My family's opinion might be a bit skewed (it's our favorite restaurant on property), but my 10 yo with sensory issues HATES CP because of the noise.
It may be more crowded now that it's not Mickey, Goofy and the Munks, but the restaurant itself can be very busy without being too loud (we've been to many dinners there when it's been packed). Can't say the same for CP.
Suzanne