Max5 has much more detailed knowledge about the 996 than I do. Only my 2 cent.
Generally speaking, as far as the engine is concerned, the 996 has not the best reputation in terms of reliability and durability. It was simply the 993 engine with a water-cooled cylinder head. And that didn't really work while the 993 (actually 964) engine was the last high development stage of the air-cooled world.
It looks different with 996 Turbo, whose engine is considered as very good and reliable. They are very sought after and more expensive.
But as Max5 rightly says, the beautiful convertible is certainly much less stressed in its life than a turbo.
Many meanwhile older Porsche fans still see the 996 as the traitor of the air-cooled design. And moreover the policy of the same sheet metal parts with the first Boxter was not exactly value-promoting. On the other hand Mr. Wiedeking who took over at Porsche round about 1994 in whose spirit the 996 was created, saved Porsche's life! with developing this car to lower production costs.
He even brought a group of Japanese technicians to Zuffenhausen so that Porsche could learn everything from the Japanese of Toyota, which led to Porsche surviving and becoming successful again.
But in the meantime all this is already history again and the 996 will also have its firm place in Porsche history.
And if the car your buddy has in mind is so well maintained, and your buddy won't always visit track days with it, but will probably cruise beautifully, then the car can be a lot of fun.
