Noise levels are important, but IMHO, not important enough to risk overflowing your tank on the living room floor. Any sort of obstruction in a single pipe durso style overflow is asking for trouble. You _need_ more capacity in your overflow than you have returning to the tank... enough to handle a clog in the drain system without making a mess.
Durso systems can be reasonably quiet, if properly sized, but they'll never be silent. IMHO, single durso style overflows are risky. Dual durso systems are fairly safe, as long as either overflow, by itself, can handle all of the flow from your return pump. If not, and a big clog happens, it can be a mess.
A properly functioning Herbie or BeAnAnimal style overflow is far safer, and almost totally silent. Problem is, you need two, or even three, drain lines per overflow to make your tank work this way. Most of the big tank makers haven't caught on yet, they're still putting one drain, and one return, in each 'standard' internal overflow box. To convert one of these, you either need to drill another hole, or run your return line(s) outside the tank.
Always look at worst case scenario. What happens, if an empty fish store plastic bag, or something similar, ends up wrapped around your standpipe? No water getting out, pump still running... is it going to make a mess? That's a situation I always test for, when setting up a tank.
With a single Durso system, you better hope you've got a real small return pump compartment in your sump, and an even smaller ATO reservoir, because all of the water in those two locations is going into the display. Will it overflow? Most likely, yes.
With a Herbie, the 2nd drain line should handle the flow. With an Animal type, the 2nd AND 3rd drains make you pretty darned safe.
Add in the fact that Herbie and Animal style drains should be virtually silent, and you'll see why they're becoming more and more popular every day. I fully expect the major aquarium vendors to start offering 3 hole internal overflows and providing Herbie style plumbing kits (probably without the gate valve) in the near future. We'll see.
. I think of them like I do the auto manufacturers that offered cassette players as standard in cars for a decade after the last cassette-playing consumer had died.
