I did upgrade from 997.1 C2S to 991 Carrera.
I'd owned 997 C2S for over 5 years and covered just over 10,000 miles in that time. (it's a 2nd car) I used to upgrade every 18 months or so until oversupply and economic events forced a decision to keep the 997 for longer. (there are worse cars to be stuck in) It used to be in the UK that a new car would lose a maximum of £5K over 18 months and you only got 24 months warranty - so it made sense to trade if you got your timing right. However after 12 months of ownership 2007-2008 the car had fallen £15,000. Rather than a 12 month wait for the car, they now supplied from stock!
Being not prepared to lose so much money trading up, I was resigned to enjoying my C2S for a longer term, I drove it harder than any other P-car I've owned and it rewarded me more than I thought it would (so another lesson learnt - no more garage queens!). Only expenses I had were servicing, gearbox cable snapping, battery & tyres. However in 2013 it was going to need it's next major service, tyres, brakes, Alarm work and the RMS leak had returned. I figured I was going to need to spend money on it.
I was an immediate fan of the 991 but felt that the pricing was wrong. Job security was also a concern and I'm still a bit miffed that Porsche's no longer hold their value. But that is the way of ubiquity. That said, I still find 991 quite a rare sight on UK roads. So I drove a demo 991 C2S.
It was like the 997 had become a nail overnight. I'd suddenly noticed chassis flex I hadn't realised was there. Cabin noise suddenly became more pronounced. Squeeks and rattles seemed to emerge from nowhere. Could I detect a coil failure? (pickup I'm sure was more hesitant than before) My, this leather is becoming shiny.
Started to look at used 991 C2S - prices around £70K mark seemed tempting and achievable. But then I borrowed a C2 for a day. When I dropped it back, I realised this might just be a better bet longer term. The pricing was better, the delta between the models isn't as pronounced as 997 was (PASM is no longer a necessity - they both have xenon lights - the power is comparable for 95% daily driving and in fact, in the UK - makes more sense IMHO as you don't need to be 100+ mph to enjoy it!) and in 5 years time - I fairly sure there won't be a £10K difference between them come trade-in.
Then the dealer made me an offer on a new car I simply couldn't pass up.
Now the owner of a shiny new 991 with the spec I want and I have returned to an old habit I had of looking in the garage at my car for no other reason than enjoying the vista.
--
991 (what a car!) XC90 - Black/Black 2 kids, 1 dog