I LOVE my AC HOBs, 11 out of my 15 filters are ACs and I will be replacing the ones that aren't with ACs when needed. I like the way I can vary the media in them as needed and the fact I don't have to pull things apart to clean them. The 110 is the largest is it not? I actually run 2 70s on my larger tanks because I dont like a single flow for water circulation so doubling them up solves that issue. I've had a few noisy impellers, but most have quieted after running awhile or with a good cleaning.