the pump is great! its actually too silent.. haha... a lil less powerfull but much better and the controls are cool.I would just get the 6000, I think 2377gph would be a bit much for a 125g. The dc 6000 is equivalent to the Quiet one 1400gph you had, but it's a lot quieter. If the quiet one worked fine for you than I would stick around the same amount of flow.