BP is the only survival game/mod worth playing right now. DayZ SA development is painful and almost comedicly slow.
But BP is not currently a proper survival game.
BP
1) Pickups are 50% weapons, 20% useless rubbish, 10% food and 20% tools
2) Zombies are not dangerous. Easily outrun, and easily kill
3) There is very little to do other than collect weapons and avoid kill on sight
4) Very little need for food and drink, and hunger prompts are non-existent as far as I can tell
5) Vehicles are there on some maps but is there a real reason for them?
DZ:SA
1) Pickups are 20% weapons, 30% food and medpacks, 20% clothes, 20% tools, 10% rubbish. It also has the chance of damaged gear
2) Zombies are dangerous and better avoided in most cases. Some can be outrun, but not all. Some of this is due to coding bugs but still...
3) They have implemented fishing, hunting and cooking as a start. More to come
4) Hunger comes on very quickly, and should be monitored constantly
5) No vehicles yet, but will be soon, but again not sure why
If you want a survival game which should become more polished then play DayZ:SA.
If you want a slightly more polished game which might become a survival game, then play A3:BP.
If you want a game with no bugs, then don't buy an alpha.