they ride like a garden hose wrapped around your wheel, rolling resistance sucks, you can't repair them- I agree. But I've been having a rash of tubular flats lately and I decided to put a tufo hi-comp carbon on the rear wheel of my hed h3 set. 6 miles to go on what turned out to be 55 miles and all of the sudden-- thud, thud, thud. I pull to the side and stop- the tire hasn't deflated- then I see it- the top of a nail sticking out of my tire. I had to use pliers to pull it out- yes it went into the rim, but, luckily for me, it wasn't long enough to exit somewhere else. I didn't have sealant in there, the tire was just 4 days old- but I put some pitstop in and the tire- with holes on both sides, actually held enough air for me to ride home without bottoming out. I just ordered another one- I have 2 sets of clinchers arriving for the rest of my fall/winter/early spring outdoor riding on tuesday (thank god).
Now I have to repair the rim, which isn't really a big deal.