As many of you know, Steam now offers a profile level system. Upon leveling up, you seem to receive rewards (eg ability to receive cards from voting on Community Choice, more friends).
As far as we know, what are these rewards, per level? Are there any rewards other than more friend slots? I know that each level gives five more friends, and 10-level milestones grant higher booster pack drop rates (20% more each milestone up to fifty).