I've got a set with those same exact offsets in Anthracite, I bought them before I even had my Cayman, but then I got a Cayman and I never got a chance to run them on my Boxster. I was thinking about picking up another set now that I saw the group buy going again, and this time going with the 18x9 front wheel option, which I didn't get the first time around because it wasn't listed as one of the fitments for the Boxster.
They look good in the photos, and in my opinion look better in person, and the styling does look very good in person, the i-beam spokes really seem to give it "depth" if that makes any sense.
I've probably got 10,000 miles on them, mostly highway driving to/from the track, and track driving, and so far they are doing great, even after several outings at bumpy tracks like Road Atlanta (curbs such as T3) and Sebring.
I've seen several other sets (on Caymans) and they have all been anthracite, which is the color I have, so I can't comment on the other colors. I don't like their silver, it seems too bright, but it does look good in these photos and probably looks really good in person too
My Boxster is still up on jack stands and probably won't be coming off anytime soon, certainly not before the end of this group buy, otherwise I would throw on those wheels and take a photo (but it would not be representative since I am running larger Cayman diameter tires)
Steve