I use TCs on one wheelset, 5k with tubes on another and 5k TL on a third.
I prefer the TCs over the 5k any day of the week. As per Aerocoach, they are a wee bit faster then GP5ks, although BRR says differently - as far as i am concerned, they are close enough to not really matter too much. The superior ride quality of the TCs is what seals the deal for me.
That said, for my TT/tri bike, however, i run 5ks with tubes - mainly to avoid the risk of flats (my deep sections are quite old and not tubeless compatible).
There was a thread on this topic a month or so ago - you should try to find it.