Thanks for the reply. After more research I decided to go with them. Seems like a stellar deal for good quality headers. Never heard of LexTek down in Canada but will be exciting to fit these headers on!
I've gone with them, so far very happy. Certainly so for the price. They fit pretty well, and sound great with my Yoshi Alpha slip on.
I installed them and test rode it without changing my fueling, and noticed a little more oomph in the mid range. I didn't try much at top end.
I have installed the Woolwich racing Flash kit and log box, and definitely have noticeably more power all the way through the range(haven't used the autotune feature just yet, I've roughed it in, and that's my next step). I managed to spin the wheel under hard throttle in 2nd, where before it'd just pull a power wheelie.... Hopefully going to manage to get to a dyno, likely next season, to see proper numbers. (Canada as well...)
Anyways. All this to say I'm definitely happy with the purchase. They give better power than stock, better noise than stock, and cost less than every other brand, but still feel pretty quality. I'm sure though, m4 is still probably among the best for this bike, but this is without a doubt a worthwhile more budget friendly header set, if you want an upgrade from OEM.