Andrew, I'm a big Magnus fan. Ya just can't beat the unconditional guarantee and Mike Sohms is an honorable man. As for the alignment thing...
Personally, I align them horizontally. I do so because I pull my arrow back till the BH about touches my finger. It's kind of an anchor confirmation/draw length checker thing...BUT, they will fly well for me at any angle from vertical to horizontal.
If a BH is 1. Mounted perfectly, ie, zero wobble. and 2. The arrow spine is proper for the draw weight and arrow combo...then you'll have no problems. Where guys get into problems is with "marginal" spine situations OR poorly mounted BH's. Good Luck. TomL