If you listen at 70dB I wouldn't bother with either. Sure, you get twice the slew rate (or some such nonsense) but you also probably more than double the cost, get more gain out of your source (more than likely) that you don't want to begin with, etc, etc. If you want to spend money wisely find a better attenuator for your 2ch beta22 and invest in ways to lower its noise floor.