At first I thought the pvp is 99% luck (and it is at first) but this changes later on. The matchmaking kind of sucks sometimes, I was down to pvp rating 400 ( you start at 500), but now I have a nice squad of heroes and win like 3 of 4 matches. And it does not bother me at all to lose. Doing 20 pvp matches a month gives nice rewards, even if you lose all 20 matches
At the moment pvp is the most fun for me, at some point you get a feeling what heroes the oponnent might have, and it is most important when to start to put your heroes on the board. I had matches where both waited to play a heroe until down to around 400 health.
Edit: my deck atm is a direct damage deck, with torr (a hero you get early) , ku-luo (my secret surprise that no opponent expects, he wins a lot of matches for me), errys (was way too mighty for a long time, nerfed now but still good) and cipai.
Balance patches come frequently, sometimes they nerf good heroes to useless, sometimes it is appropriate.