[naparsei]

I'm 6'4" and 225# on a good day. I have two early 911s, a 997, and a 951. The 951 is a track only car, but I've driven it on the street. Without a doubt, the 951 is:
(1) if modified, faster than almost any N/A 911,
(2) better balanced

Maintenance costs are suprisingly similar IMO, although driven by different issues.

You can fit in a non-sunroof 911, with cunning work done to the seats and how they mount. TRE is working on a car for me, and it has a modified headliner, and a much lower seat (because I wanted to fit obviously, as well as allowing my 5'4" wife to drive - so I need sliders - which I DON'T have in the 951).

The 911, although IMO opinion probably not quite the "numbers" car of the 951 (my 951, new in 1987, cost the original owner $62,000 - that was every bit and then some 911 money), is more fun to drive. No turbo lag - the engine loves to run high. Due to the weight bias, you can really put the power down coming out of a turn, which is a problem in the 951 due to turbo lag (or not, depending on your left foot braking ability and what mods you've done).

The 951 is forgiving and extremely neutral. It's easy to drive. In fact, it's a lot like my Spec Miata in that sense. The 911 is more rewarding to drive, but it's harder, and it's a lot less forgiving.

911s are a bit easier to work on, IMO, because the timing belt, balance shafts, etc. aren't part of the equation, and of course you don't have the coolant based cooling system either.

They are both fantastic cars. The 911 is widely recognized as such; the 951 has a cult following, but is dismissed by many as a failure by Porsche (I would argue most haven't driven a good example).

FWIW, I'm a 911 nut, and fell into the 951 because I wanted a track only car, and had the chance to buy mine, which had been raced and set up by an SCCA national autox champion. The car was well known locally, and it was a no-brainer for someone just getting started going to track days (7 years ago). The car has been dead reliable as well.