honestly, even with (another mod pack of questionable caliber) I would have a small discussion with users who use loops in their pipe systems (of course, we also had RP2.... soon, I know). The lag/server load created is insane... and that's with only one person; imagine 5 - 10 people with a couple of these going.... I don't have a hosting plan that can support that load (and I'm not paying extra to do so).
With gates and the changes to BC pipe, that's almost unnecessary. With logistics pipes, you just need a valid default destination (playing with the 'unofficial' release, fingers crossed for Krapht's). With RedPower2... this is all moot.
I just wish there was a better tutorial on gates on the BC wiki. I might make one, but I'm flailing blindly on most of the stuff with them (I still see strange things happen with some of my systems... not sure if the gates are working right or I'm just an idiot... I'm mixing those two answers).