I have used them and i'm currently using them. For the money you can't get a better deal than this ones. Some people say are garbage but if yo uare not racing this tubulars are ok. I have had more success with this ones than the vittoria rally.
Things to have in mind. tubulars in general are never straight, you can work them out after gluing them but some stuff sometimes is just awefull. My last Vittoria rally was awefully twisted from the factory. The servizio corsa ones are ok, not super good and not super bad either...
The guy has 2 valve sizes, pick the ones you need.
The ride is ok... At least I have no complains how they roll at all. For example the challenge criterium cost way more but I find it too sticky. Not a bad tubular but I find it slow compared with the 3x50 ones. Back in the day had a pair of clement zeta and those ones no matter how much air you were putting to them, they were soft all the time.
As for air presure, if a tubular say max 230 lbs please dont put that, in a matter of fact any tubular brand or model should ride w/o any problems between 80 and 110 pounds of air.
If you are into racing I would go with something else, but again for the price this things are pretty good. Have not punctured a single one ever, have those tubulars in all my wheels. For the riding I do are ok, no need to go to the 200 bucks ones at all.
Dunno, good luck. If you dont like them just let me know to buy them from you
I like them.