my current daily driver is a 83 911 (130k on the clock) and love it I am looking for another subaru for snowboarding now though. i actually chose to keep my 911 over my 03 wrx wagon awhile ago and glad i did. yeah older cars need maintanence but, honestly all cars do. i dont have much experience with the 964 but, do with the 996s and obviously the 911sc's. as with all the different changes throughout the years its really on creature comforts, the newer the car the more comfy its going to be.
ive had my 911 for about 4 years now and as far as maintence goes oil changes are a bit more only due to the fact i use 12 quarts per rather then the subarus 4.5 quarts and change a fan belt. Some things are more expensive to repair on the porsche and parts are readily available everywhere but, pelican parts is really good about shipping and usually have parts in 2-3 days when ordering.