I'd pick the A-frame as well, just because I've used it and trust it. No flies on the NPT, though, so I'm in agreement with you that whichever is the better shooter is the one to go with.
Whenever I start debating myself (in my head) about what bullet to use for buff, I recall an article, or maybe a book chapter, that Craig Boddington wrote many years ago where he talked about using Sierra Gamekings (I think) in the 375 H&H to take buffalo back when "premium" bullets were a rarity. So I figure, if GameKings will work and did work years ago, I shouldn't worry myself about whether to use a TSX, Partition, or A-frame too much. Put a bullet where it needs to go, and you should be able to kill them just fine.
