I have one on my little 30g. Seems like a good skimmer to me.
When I researched the purchase a few folks seemed to have microbubble and noise issues, there were a couple of others that I don't think ever got it right, overflowing and such. Again, this seemed to be limited to just a relatively few people.
I don't really have microbubble problems (simple pipe fitting mod on the outlet) nor any of the other problems I read about. It's a little noisier than I thought it would be but that probably comes with the territory since its not surrounded by a stand. You really have to watch the grommet that guides the impeller to the pump body. It's easy to mount that little part improperly and in general the grommet seems to wear if you don't get it right. This really ups any noise you might experience. It's no problem getting new grommets though, Doug at Deltec is great to work with.
My unit produces consistent, reliable nog. Nothing outrageous but this is on a little tank. Bottom line, I would do the purchase over. If I was getting a deal like you suggest it would be an even sweeter decision.
If you do end up buying or have any more questions before the purchase let me know, I'd be happy to try and answer.