the "sports" seats in the zhp don't grip as well as the sports seats in the coupes. (at least i'm comparing my zhp seats to the seats in the 335i, so not quite apples to apples)
after going tracking my car a few times, i notice how much i move around in my seats, even druing street driving, when taking fast corners. the coupe seats huged me much better during a test drive.
that said, alcantra does have better grip, but it the frey fast and wear out faster. if you the car is still under warranty, they'll replace it for you, but afterwords its out of your pocket.
zhps are sweet rides imo. 3 years and not a day has gone by when i regret my purchase decision ^^ well cept that day when i test drove the 335i.. but they are different beasts altogheter.. or so i tell myself.