I have recently started kegging and doing closed transfers from FV to keg. After reading many reviews and watching many videos I settled on the process and equipment detailed in
this HBT post including the FlotIT. So far I have flawlessly transferred 3 batches with this process (FlotIT on the FV side and a SS pickup tube on the keg side). Clear beer moved to keg, yeast and trub and gnat wings remained in FV. I crashed each keg for 2-3 days then force carbed with 10 PSI CO2 for a few weeks. The first half pint from each keg was yeasty and thus poured off, and since then just clear and satisfying beer. Remember, the kegs have the SS pickup tube and only the FV had the FlotIT at transfer.
My upcoming experiment is to prime a keg with sugar instead of CO2. I figure this will give the beer another few weeks to condition and improve flavor at ferm temp. But since I expect a fair amount of sludge at the bottome of the keg due to priming with sugar, I will put a FlotIT in the keg instead of the SS pickup tube. Given my observation of the FlotIT's behavior at the bottom of the FV during closed transfer, I expect it to perform well in a sugar-primed keg.
I was amused by some of the "...it's over-engineered..." comments. You only know when something is over-engineered if it works flawlessly, as designed for the purpose, every time. There are 3 things I want over-engineered: Diapers, brakes, and floating dip tubes.
But alas, my only experience with floating dip tubes is the FlotIT. At this point I have no reason to try a different one.