Heres a bump for a good thread....and a little bit of an update.
I run a turboflotor multi on my sump, and was having trouble getting good skimmate consistently. 
I added a needle valve to the air intake to the needle wheel, and I also tried plumbing my overflow directly to the inlet for the skimmer pump.  I had some plumbing issues with this setup, and since I wasn't able to get good, consistent water feed to the pump, I had to go back to just pulling water out of the sump to skim.  
However, the needle valve has been a big help, and now I do get quite consistent skimmate, good quanitity and concentration, as well.
I actually very rarely make any adjustments to the water flow valves (for adjusting the water outlet flow), I do almost all of my adjustments with the needle valve.
Just thought I'd share, it's sortof a success story, thanks to AC and everyone else on here who contributed to the 40 pages or whatever this thread is now...Thanks all.