Well, where do I start? Horribly impractical, not particularly comfortable, maintenance needs to be kept on top of and is expensive. The 2 litre twin sparks drink oil at an alarming rate (this is "normal", check the level weekly) the v6s are front heavy and prone to understeer, rear suspension is complicated and expensive to repair when it goes wrong (it will go wrong) front lower wishbones are made of chocolate etc etc.
However, treat them right and they reward you with a grin that is hard to beat. I LOVE my GTV. So much so in fact that I have actually bought the car TWICE! At nearly 20 years old it still turns heads. I frequently get chatting to people in petrol stations (I think you guys call them Gas Stations?). The amount of people you see in the rear view mirror sneaking photos is also quite amusing.
Even in the UK a 916 GTV is a VERY rare sight on the road. I've owned both the V6 version and the twin spark (which is what I currently have).
The V6 is now getting expensive (around double the price of a twinny). It has a glorious engine note and is pretty quick, even by modern standards, but they suffer from understeer due to the weight and front drive chassis.
The twinnys are much better balanced and although around 1.5 seconds slower to 60mph, I find them more "fun". The twin spark is a great engine and has that classic Alfa "rasp" to it. They love to be revved and on a tight twisty road there's not much that'll keep up with one, if driven properly. Handling is surprisingly good for a FWD chassis, possibly one of the best ever created.
All in all they're very much an Alfa Romeo. Flawed, expensive to run, stunning to look at and great driving experience on the right road. The Twin Sparks are presently under valued and are disappearing fast, as the costs of maintenance are exceeding their market value. The V6s are still fairly plentiful, but prices are climbing.
I love mine and it's going nowhere. It's scruffy in places and I'll probably spend more than it's worth to keep it alive, but you can't put a price on the grin it gives me.