I can only go from what I've researched, which include those, plus some pet buffs, or if you want to switch the buff. Plus the mounts are faster and can sprint more often. Also avatars, the one I saw as examples was +2% str. Many of the cards needed for the better sets only drop on card packs, they don't drop in the game. Not only do you have your card set bonuses (which are a heck of a lot bigger than .06% damage, I saw 20% damage resistance for example) but you also get your bonuses for filling out card books.
Stack slightly better, on slightly better, on slightly better etc you're going to see a noticeable difference in every single stat.
Probably won't affect anyone who isn't playing it for the endgame of the MMO, and of course you /can/ raid Blackwing Lair in greens.