Can't comment on the Ecco. I've heard bad things about the range for a long time so I went for a ProII
I thought the TT was quiet when I got it. but after switching to an EheimPro2 3 years later after absolute kaboodles of problems I suddenly realised what quiet was.
The TT is reasonably quiet BUT one problem is it's vibration. In my cabinet the vibration amplifies through the wood of the cabinet and it was pretty noticeable when TVs etc are not on!
The Eheim in the same cabinet is absolutely silent. No hum through the cabinet frame at all.
As a poor comparison I have a small Boyu like the Eden and thta is pretty noisy and rattly. however I couldn't hear that over the hum of the TT/cabinet. I can hear it now though. lol
Add to that (In my experience):
The TT is pretty cumbersome and much bigger than its Eheim competitors (same turnover)
The top is hard to get off and on after a while. Iused to have it on the floor and try and inch it on from side to side.
The 'prime' button pulls water out through its own seal, after the first few weeks of use needs Geoff Capes to push it for you.
It is pot luck whether you get a seal or not.
The impellor is pretty noisy in comparison to the Eheim.
It vibrates much more and of course as explained vibration causes even more noise than the impellor due to it echoing and resonating through whatever surface it stands on or is in.
The media is no where near as good as the Eheim even though there is much more and also more trays. More for the sake of it so it seems.
It does have a major plus point though - The hoses are better than the Eheim, more rigid
That is IMO it's only plus.
Of course there are many who will not have these problems but for me that is what made me bite the bullet and just shell out that bit more. I like silence
Doesn't answer your original post I know as you haven't listed Eheim as an option and the TT may well be quieter than the others. Just pointing out that there is no way I would choose the TT if noise is the concern. Most definately wouldn't be in my bedroom as the wife wouldn't be able to sleep with the noise. I can sleep through almost any noise as I only go to bed if I am really tired
As for the comparison in turnover. The Eheim although rated the same is turning over more when cleaned (not measured just from viewing) and most definately through use as it doesn't clog up as quickly as the TT.
Peter. You are me circra 4 years ago. I laughed at Eheim owners who defended their pride and joy telling everyone they were much better. I labelled them the EOC (Eheim owners club.) I told them that IF there was anything better about the Ehims than the Tetratecs then it certainly did not justify the huge difference in cost. However I was wrong. You cannot underestimate how a filter that was twice the price of the TT is easier to use, produces better results and is silent (yes properly silent). It is worth paying 3 or 4 x the Tetratec and that to me more than justifies it. I just wish I hadn't skimped 4 years ago and then I could have the money I wasted on the Tetratec and bought 45 lottery tickets instead.
AC