Fuzz
Go for the Devils - I'm a UK rider, too and have had them on since new for a year now and love the sound and look:
But, to be honest, there are some issues, only minor IMO:
- db killers need a rivet popping to get out and then you need to fabricate/get fabricated a bolt/nut fixture on each db killer if you want to reinsert and secure them
- however, I haven't bothered putting them back. They're a tight fit to say the least and the sound is way too gorgeous and I haven't attracted any unwelcome attention. They are loud but I find that is a help when filtering through stationary/slow moving traffic
- my dealer fitted them and in so doing removed the undertray, which meant a lot of roadmuck this winter came up and seized the seat lock. Bent my key trying to force it. Not a problem now I'm aware and keep the lock well clean and oiled. If you fit them, see if maybe the undertray can stay
- I get a bit of gas leaking out of the joint between the pipes and the top of the OE cat pipe, evidenced by bubbles forming when wet. I don't know if this is a manufacturing or fitting problem, but in any case I'm looking to get this sorted when I get a cat elim fitted at next service