The other day I drove a standard Cayman S with sport chrono but no PASM through some very tight winding roads. The handling was still impressive but on hard driving/cornering it felt a little sloppy compared with the Cayman GTS with SPASM I had driven previously on similar roads. Some how I even got the CS to understeer a little into a very tight 15mph sign posted corner.
Personally, for my style of driving I wouldn't settle for anything less than SPASM. I haven't tested a standard CS with PASM only but I'd imagine it would be a significant improvement.
I thought the comfort was fine on both the S and the GTS models, but the handling of the GTS during hard fast cornering was far superior, presumably due to the SPASM which also comes with up-rated anti-roll bars. The GTS models as you would expect are nearly on par with GT models these days and surpasses the old GT4.
I also noticed that the PTV does help with fast cornering but probably something to get used to as it feels a little like oversteer but isn't.
I think the handling of a standard CS is probably close to a GTS without the PASM button switched to sport.
Note PASM is only a 10mm drop, SPASM is a 20mm drop and the front spoilers angle up so I don't think they are prone to scraping. Although I did get the GTS to scrape a little on extreme tight cornering but I assume that was probably the plastic wheel lining inside the wheel arch or something else but not the front spoiler.
I measured the height of the front lip spoiler on a SPASM GTS and it measured 155mm which is not particularly low and 15mm higher than our 3 series m-sport which has an m-performance lip at 140mm high. BTW my Audi is 130mm. So whilst the Cayman looks low I don't think it is that low for a sports car and the wheel base is short so it shouldnt bottom out much in the middle.
With that said, I think careful sideways exiting of steep drive ways with dips or humps is still advisable with SPASM. Though I think the lip is plastic underneath so if you scratch it up a bit it doesn't really matter.