I'm lefty also, and don't have problems with toss or inconsistency, angles or pace, but I also have problems winning the majority of ad court points.
Gotta consider, maybe the opposition tries a bit harder returning my serves from his ad court, maybe he can angle short returns to my forehand (my weakness), maybe he rips topspin backhands off shoulder high balls (RussellSimpson and JoaroSoares), maybe he actually has a more consistent return off the ad side, maybe he's not a duffer too.....
No problems winning ad court points against lesser players, it's the guys who beat the crap out of me that wins the majority of ad court points against me.
Sometimes, you gotta consider..... maybe dat dude on the other side of the court can affect the outcome of the points....