If he's getting a 4870X2 i'd say he'll switch cards when the 5870X2 comes out, lol.
Lifetime warranty is sexy, but maybe a 3-5 year is enough (if he doesn't sell his 4870X2 later on, lol).
Anyway, you can go the "more goodies" way or the "more warranty" way. IMO, either is a good path to take.
Esop!