I'm relatively new to this as well, but seems to me that the forest is sort of lost through the trees on this topic...
10, 12, 15 g.p.p. probably doesn't matter if you have a sharp broadhead and you hit 'em in the boiler room.
Pass through shots are very nice for us less skilled trackers, so that might be a reason to use a two blade or to go heavier, but it doesn't sound to me like your current set up will hold you back one bit chasing whitetails.
It is tough given our consumer culture, but I try to spend my archery time shooting, not tinkering with gear and spending more money.