As a cayman owner and pretty active member on the cayman forums i'll give my account. The RMS problems are much more common on the mezger engined cars than on the 987's. You see that problem rarely on the cayman platform. Rather, if you are going to track, first-gen caymans are known for oil starvation problems and anyone who runs r-comps or heavily track their car ends up modifying the oiling system. Most run with a deeper sump available from LN engineering, or an accusump system which cost ~1-2k installed depending on the route you decide to take. On a dedicated track car, you'd probably want to run a 2 quart sump and an accusump. These problems are resolved with these 2 mods and everyone does fine with them. Other than that, these caymans are really great out of the box. Also, very little has to be done to get the full potential out of them. With GT3 or TPC sway bars, GT3 or RSS front control arms (front maxes out at -0.8 degrees of camber and camber plates still won't get you much), a good set of tires, and some good fluid and pads and you're really ready to go. These cars really perform spectacularly with a good set of bars and some negative camber. The '09+ 987.2's alleviated the oiling problems with a dry-sump oiling system and do not need any modifications.
As for the maintenance everyone complains about, this has been the most reliable car i've owned. Sure, wear items like pads and rotors may cost more, but my maintenance history has not been bad AT ALL. In comparison, my friends with BMW's and other cars had way more reliability problems than i've had so far.
Jet Black / Gloss Black Grilles / 8000k D1S low beam / 6000k HID fogs / GP Thunder 8500k angels & cornering bulbs / black reflectors / gloss black vinyled window trim / tints / smoked rear turn signals / black roundels / AC Schnitzer roof spoiler / VRS style decklid spoiler / Matte black Stripes / Rear fogs / matte mirrors / 19" LM reps / APR lip