For naxx I personally prefer LC / SR with guildies, however GDKPs in their current form are helping lots of people raid with a wide array of other random players and, in general, everyone is having fun and gear is being well distributed.
It is hard to think of a better system than GDKPs for the game without additional development.
In the end the troll hunter is correct, GDKPs and gold buying should be treated as separate things.