Nothing to add with the AMAX, but in the 150 gr weight, I just got some SSTs and found my accuracy node. Tried "a better bullet" with the Accubond and like you, I never could find a good group. But I'm not sure I'd notice a difference between an economical load like an SST over a more expensive projectile on deer at the practical ranges I'm likely to shoot, and I'm also pretty positive the deer (or hog) won't notice either. Hard to beat the Sierra (or SST) for the price.
I suggest you stay with the Sierra.
Here's my load: 150 gr SST, 43.9 gr Varget, Lake City Long Range (LR) brass, and CCI primer.