I paid a not-so-small fortune for my 2-into-1 headers, but they're lovely and have given the engine new lungs, no doubt. Definitely a case of getting what you pay for...
Hmmm, can't say I fancy the single sided look, you could go "senna'esque" with an underseat can, not easy with the older suspension loop-arm arrangement though.
Works for us too on the Snot (Monster 583) Lin - and with it coming out on the RH side (as you look from the rear), it does save it being 'squashed' in the event of an off too - as we found at Brands trackday