I love the Alcantara seats in my Stradale but it does making getting in and out just a little more difficult. That's what they're intended to do - prevent sliding. Fine for a weekend car but note sure if it would be good for everyday. It does look really nice though.
According to Finnish price list Cayman S and Boxster's have seats in Alcantara / leatherette. In some countries partial leather might be standard but I think that in countries where Boxster's come with Alcantara so does the Cayman S.
Is it me? What is the appeal of Alcantara? It is a synthetic polyester fabric. That doesn't sound near as appealling or durable as genuine leather. If it's the Ultra Suede people find appealling, you could just as easily have genuine suede. Granted, it would be more difficult to clean, but it isd still leather. You can always refresh the Nap by using a mild sandpaper.
IMHO, I'd rather have leather as opposed to some fancy Naugahyde!
Alcantara is actually a VERY durable material. It is an Italian synthetic material with excellent durability - stains just wipe off with soap and water; that's why it is used in some sports cars; genuine suede would be an absolute nightmare. We have it on our dining room chairs but I personally prefer leather seating in a sports car. But they do look nice.
I had Alcantara in my seats in an S4. It is very nice...sporty and elegant at the same time. It does make it a little harder to slide in and out of the seat, by design. Not a big deal, just different. I would buy it again in a heartbeat. It is very durable and I never had a problem with staining or wear.