I've been thinking about it for a while and I'll probably go with the 2000. You get the same 1000l/hr air flow with only 60% of the water flow-hopefully a drier foam than the OTP-2000.
I was originally going to replace the OTP-2000 with the OTP-1000 and I asked Mathieu at goreef to see if it was compatible with NWB-150. He got in contact with tech guy at CoralVue and he said that the fittings were a different size and even if I modded it to fit the skimmer, the pump would burn out pretty quickly.
I'm hopefully going to be getting a bunch of frags this month, so it will probably be the end of next month before I can get the 2000, but before I order it, I,ll ask Mathiue to run it by the tech at CoralVue, just to be sure.
P.S. I've been running this skimmer for about 2 1/2 months, and I am slowly coming to the opinion, that as it stands, it is a piece of junk. I was originally thinking that the reason it performed so poorly was because I have a very small bio-load, but I'm starting to think that is a very long way from being the main issue.