What do you think is the more social portable? Vita or 3DS? Online multiplayer, # people who have it, etc

I'm thinking of buying one. I like the games collection on both. But online multiplayer games availability and finding other gamers around me matters just as much too.. what do you guys think? Which has a stronger backup in these games.. and in general popularity? With the Vita price drop my decision got harder and looking to find out if anyone knows more about irl.. I've been inactive in the gaming community for a long time... I'm leaning towards the 3DS because of the classics but haven't run into many online titles, a few like Kid Icarus.. are the servers/matchmaking pretty populated on these?