Being also a car-nut, petrol-head ...
If you really wanyt to know what it's like up-front,
Check
http://www.evo.co.uk.
They have had many Porsches as long-termers and report on it monthly.
On the home-page, scroll down untill you find "Fast Fleet" and goe back a few months. I think they said goodbye to their 2004 Boxster S a month ago. All was perfect, apart from rusting-brake discs, a small leakage and a stuck window if i remember well. The brake-disk rusting happened when at a stand-still for a couple of days and was sorted under warranty. Looking from your mileage that's not likely to happen.
O yeah, these guys have a rather heavy right-foot so the fuel-consumption in there is on the high-side for normal driving. The same for other consumeables like tyres and brake-pads.
They have experienced a few problems, but most of them where sorted quickly and under warranty.
I've driven a few of these cars (and similar ones) and the Boxster S definitely is a good choice, a comparable one (but much cheaper) is the Nissan 350Z.
In other words : buy the magazine. Especially last months where they tested the 2005 Boxster against a whole bunch of other performance cars.
Just briljant.
Have fun reading...
GReetz,
S.