training to failure vs other training methods

So, in general, I'm looking at exercise as a stimulus for adaptation and it's pretty clear that, excepting animal models of compensatory and stretch-induced hypertrophy (and hyperplasia), resistance training is the way to go for muscle growth. In particular, it's the high tension that makes RT such a great way to build muscle (e.g., eccentric contractions, which produce greater force / unit muscle, are especially potent for muscle growth).

So (I'm going somewhere), this suggests that heavier weight, that loads as much muscle as possible (you've got to activate the fibers if you want them to adapt) would be a nice stimulus for growth. Heavy loads means high intensity (and activating more muscle) and taking sets to failure, means progressively activating more motor units during each set as the set nears that failure point. Just keeping things simple, the above suggests that a high intensity regime, with sets taken to failure (in some configuration of volume balanced with frequency) would be the way to go.

Second Notion: Progressive Overload. If you're going to progressively stimulate using the above notions, you'll have to lift heavier loads over the long haul. This will require some way of controlling the insult (inroads, damage, stimulus) of training and in taking sets to failure (vs. cutting short of failure), you've got a very simply criterion for knowing how many reps to perform and how each set (or many of them in a regime should be performed).

Opposing points (POWERLIFTING w/o training to failure): You can make tremendous gains in strength w/o training to failure. Hordes of powerlifters have proven this time and time again, and with that strength (assuming nutrition that progresses bodyweight and muscle mass upwards) comes a shit load of muscle. An AGGRESSIVE "powerbuilding" regime that programs in strength gains (in whatever kind of periodized scheme a person chooses) is a great way to make gains, too.

VOlume training w/o training to Failure. If you look a the training regimens of tons of highly successful IFBB Pro's and many very large guys (competitors or not), MANY (MOST) of them do volume training with short rest intervals and arguably do not train EVERY set to absolute, mind-bursting, shit-in-your-pants kind of failure and make great gains that way. I've suspected that years and years of training mean that many highly advanced guys can produce a ton of force with relatively less effort - enough to create a powerful hypertrophic stimulus - and have learned intuitively how much volume they can get away with and not over training (and still produce a growth promoting effect). (Watch closely during video of Lee Priest training and try to guess what's going on with him mentally - seems to me he is a great example of someone who has a mental strategy to push very deeply into a set beyond what most folks would / could do. ALSO, most of these guys have TREMENDOUS genetics, too, so they might grow well from what others do not - so there are likely biases in trying to glean too much from this training style.)