by the way, if you go with the tire rack and have them shipped to your installer, ask before shipping them how much they charge per wheel mounting. I paid $170 (OUCH!!) to have my Goodyears mounted. About a $100 to much me thinks!

I have an 03 Boxster with 18" wheels. A recent purchase. For all-season driving in the NE, I switched from the Rossos on the car to Kumho ASX all-seasons. I had had them on my SC, and was satisfied.
The Rossos, except for flat-spotting, are very smooth and give a quiet, splushy ride. But they aren't suitable at temperatures below 40 F.
The Kumhos don't flat spot and give a stiffer, sportier ride, but at times on accelerating, I hear a "boomy" type noise from the rear. Seems to be noisier at highway speeds. Gas mileage also dropped 10% based on one fill. Maybe just a breakin period thing. They were really noisy coming out of the dealership after instal, and then quieted down after 10 miles or so.
I'm undecided whether to tell the dealership about it --waiting to see if things improve. Concerned about balancing and alignment. Can't believe the tires weren't installed properly at my Porsche dealers at $35 a pop.

nexen n3000 on 2000 s
 

340 treadwear, low noise, great tread design, very sticky, good ride. Got these at Les Swab. Hold like glue.

I have the ps2's are good for daily spirited driving but when I get on it especially around turns the tires will break loose. I am switching to the BFG drag radial for the back wheels so traction wont be a problem anymore.

Trying to figure out new tires is one of the great sports for Boxster owners. I had Rosso's on and only got about 8K on the rear. Nice tires ,but? One of the people in the PCA Chapter I belong to suggested Kumho SPT's. He puts a lot of track time in with his boxster plus everyday driving. I took his suggestion and put on a set. $528.00 out the door. I have now had them for about 4K and am quite happy. Rear thread still like new, quiter than the Ross's, nice on wet, and still haven't met my rear end on a curve. To me they are what I need for my driving style which is back road racer. Ed