Cheap ammo is fine for everyday shooting, but the expansion on that TSX bullet is nothing short of amazing. If you’re using an AR for your only home defense weapon, as opposed to a shotgun, I’d probably want to have a magazine or two of that stuff loaded up to use in the event of a home invasion.
Your piston gun is not going to get fouled up as much using the cheap ammo either.
I just watched the ballistic gel test of that bullet. Wow, that expansion cavity is going to ruin internal organs if the round enters anywhere in the torso, from adams apple to groin! One shot drop with that baby.