This is strictly anecdotal, but you would probably notice a difference based on the difference of technology used. I used a Remora and it got the job done, but i always felt that the skimmate could be darker. Once I switched to a needle wheel type skimmer I started getting a more concentrated and "dirtier" skim. Like I said, anecdotal at best...
I would say that unless you are experiencing specific problems, I'd stick with the Remora. It's not a bad skimmer overall.