I'm planning to try out Melissa Clark's (counterfeit/inauthentic/call it what you want but I'm making it) porchetta recipe (http://cooking.nytimes...) but am curious about her approach. She starts out by blasting it at 450 for 35 minutes, then moves to the low and slow approach. Based on the comments I'd finish it at 275 rather than her recommended 325.
I've always done pork shoulder recipes (bo ssam, pernil asado, etc) the opposite way, ie start low and slow and finish high. Can anyone here tell me why you would start high rather than low?