Can't help you on 7mm & .30 cal but I've been using the 90gn .257 cal bullet with a great deal of success. They load easily, group well consistently(I suppose because of their similarity to the MatchKings) and knock down game in a pretty wicked manner. The stuff I've primarily used them for has been soft skinned game like roos but nonetheless the game got a very nasty shock. :wink:
That said, I'm not sure I'd use this particular bullet on game like pigs which have a thicker hide and really need a spitzer or softpoint for the best penetration.
For the bigger cals, however, Sierra probably has a heavier jacket on the GameKing HPBT. I'm pretty sure you can't get as good a bullet for the same price and you can certainly pay more for one that's alot worse.