Throw this in the anecdotal evidence heap.
I managed to win a duathlon today on TUFOs (actually half a set). I ran an S3 lite (<215 g) on the front at about 120 PSI and a Vittoria Nuovo pro on the back. I did keep the pressure down, based on the feedback from here, because I typically would go about 140 psi. The funny thing is after all the TUFO bashing I ordered a set of the Vittoria CORSA SX (slicks), but they didn’t get here in time for the race.
I know I would of gone faster without the TUFO slowing me down, although I really won the race the race thanks to a 17:36 opening and a 17:20 closing 5K. Average about 22 - 23 mph but it was a 4 loop course with 4 turns per loop, which definitely hurt my speed as much as the TUFO.