I think the fluval 404 is a great filter, quite well made. They can get noisy-ish as they get older, but the noise isnt anything really loud unless there is a problem.Turn over does slow down as they get dirty, but even with a lower turn over they still seem to do the job.I done away with the carbon and just filled all the compartments with ceramic noodles, that slowed the filter a bit, but it still kept my tank clean.I had 3 fluval 404's on my 6 foot tank and had no problems.So rather than one filter go for two smaller ones, then when you have to clean them, do them at different times,that way you will always have a filter that has sufficient bacteria.
You could always go for two bigger filters, budget permitting :lol: