I went back to playing doa5 online yesterday and it seems to be a bit more active, quite a few lobbies were up and found a few matches in ranked, mainly the same 2-4 people tho. but noticed theres still too many people with good win/loss ratios who are scared of fighting anyone who they think will give them a challenge cause of their poor ratio getting tarnished and decline the match.
Got SFXT as well for the vita the other day (sold doa5+, the online is just botched) and even tho that game is generally unpopular, it still has tons more online than doa5.
I can't stop playing doa tho, it's just my favorite.