What's the best engine oil to use on a hight torque performance rated engine ?
I've heard some good things about the 'royal purple' brand - is this a high quality performance rated engine oil or just a lot of sales hype ?  

well now....lemme see. as a former carquest employee of almost 12 years and an avid to seasoned high performance engine builder,i will say im a SYNTHETIC kinda guy. some are better then others people say. and no royal purple is not all hype, its a very good product. so is amsoil and mobil one. ill list the benefits and detractors of most synthetics and let you decide.

benefits:
1-by far less thermal breakdown
2-better lubricity(to almost a fault, dont use for break in)
3-almost no acidic residue from breakdown
4-better at transfering heat from surfaces
5-it all translates to fewer changes
6-its okay to let the car sit for extended periods of time(due to no acid buildups)

detractors:
1-cost
2-availability
3-cost
4-some wont interchange well with fossil oils
5-cost
6-not to be used for breakins(too slick)
7-cost!cost!cost!

now you decide.  

I think you forgot to mention "cost" on the detractors list!  
I've been a Synthetic kind of dude too for years now. Mobil-1 for the most part. I've also used Quaker State's Synthetic blends too. Would you rate the purple stuff better that the other types I listed here ? I'm not up on the cost of the purple stuff, but I don't scare easily when it comes to high quality and performance over buying something on the cheap at Walmart. I'll go high-end every time.
I like over-kill, personally.
I hear you about not using synthetics for break-ins too.