In my experience roamers and non-lane supports are extremely underused in pubs.
I play roaming 5 whenever I can, but I don't play much str support. I've been meaning to play more pudge, sven, wk and alch though.
WK being one of the best carries also makes him somewhat underrated as a support.
Semi related jakiro roaming 5 against nature's prophet
http://www.dotabuff.com/matches/1174362173
It's super satisfying to keep enemy carries/rats at low level and steal their farm. Canceled his clarities a bunch of times, even got a kill.
I'm just waiting for the day that I get to play support riki as an antijungler. Just afk follow them and get free xp, good stuff!