I benefited from group dungeon runs a lot from mid to high levels, especially in terms of gear. Labs->GK was an obvious progression. Now that my guild (and general) population has started to decline a bit I have gotten more interested in crafting. This means quite a bit of solo grinding as no one rightly wants to group up to farm consumables. I don't think either option is better, but I did find the cooperative play immediately rewarding. In the end I hope that active players will naturally group up into guilds, or just in-game friends to help each other, and that includes both receiving and giving assistance even when it is not 100% necessary. The grind could be alleviated--especially in quieter times--with more resource pooling, but I don't think mucking with loot mechanics in reaction to population is the answer.