Mike's awesome. Great customer service and his work is top notch. I just installed my header yesterday. It mounted up without any problems whatsoever. Huge weight savings and it sounds amazing with my Termi slip-on(pics and video clips to come).
To answer your other question, a PC3 is not mandatory with this midpipe since it's got an o2 sensor bung.
It's $275 shipped to order one and $215 (shipped back to you) to have yours modded. Mike usually sells out pretty quick so you might want to either call or email him and find out if it's ok to place an order. From what I understand, he's always taking headers if you just want to have yours modded, and that's a 2 day turnaround.
the full system i was looking at was like $900. This header with my gytr can came to $450. For now this will do for me. I can't imagine a crazy performance difference from the mjs header versus a full system. Maybe a hp or two but is it worth the money?
Im thinking that a full system isnt worth the money either. The amount of HP gain isnt worth the price if you ask me. Im really leaning towards sending mine in unless some unforseen person says something that will make me think otherwise.