I have a 120g tank and am currently using a Mag 9.5 return pump. I'm wanting to replace it with either a Tunze or Eheim. The top Tunze Silence flows 792g/hr and the Eheim 1262 flows 898g/hr vs the Mags flow of 950g/hr. Is 792g/hr enough flow? I do have power heads and could add another. This is in a 30g sump/fuge. I'm leaning toward the Tunze. I'm hoping for quieter and less heat. Thanks said:+1. I'm running 1260s (throttled back, even) on a 165 and a 210, and a Tunze Silence on a 105. I've not measured it, but with head pressure from sump to top of tank, the Tunze appears to provide substantially less flow than the Eheims do, but still plenty for my purposes -- I like slow, quiet, microbubble-free drains and returns. As long as you're using in-tank pumps to provide circulation and flow, that works fine.
All three are quiet; the Tunze is probably a little bit quieter, but not a lot. I've only been running it for about six months, so I don't know if the Tunze will stand up to abuse and neglect and just keep chugging along like the Eheims do, but as mentioned, the service and turnaround time on Tunze stuff is great, so I'm not terribly concerned.