I've only tried WW in top lane once, I was against sion and with ganks I lost the lane pretty fast ;<. It really depends who's he against, he has really good sustain so he's got an advantage from that perspective, but he can get harassed really easily.
My favourite way to play WW is as a Jungler, with no madreds. It only really works if I get a leash on blue, but I start with a ward + health pot + boots, then at 650 recall for boots of mobility. Then I build wits end and a frozen mallet, then get some CDR + bloodrazor. Warwick is an amazing ganker with mobility boots but I find him to be weak in team fights without getting on hit items ;p.