Depends very much on whether you want twin or single cans, how important factors like looks, weight and whether they have cats are to you, as well as (perhaps most importantly) what your budget is.

I had an Akrapovic twin can system fitted for several years which, although it sounds good, is expensive, heavy and still contains power-robbing catalysts.

I considered replacing with the OTR Akrapovic single can, but it's very pricey and doesn't really follow the lines of the bike too well IMO. OTR's own single can system put be off because the cans themselves seem disproportionately large.

I seriously looked into MTCs, but again (like the OTR Akra) didn't like the way the link pipe sits low and doesn't follow the contours of the bike. Good price though and even cheaper if bought through the forum. Scorpion cans (twin) follow the lines of the bike well and I nearly pulled the trigger on some, but in the end decided to go single can so I could fit a big homemade tool tube on the right and save the maximum amount of weight.

Final toss up was between MTC and Exan. MTC wins on price, but for me the Exan tipped the balance based on low weight and how it looks, and the fact it was only a few quid more expensive (with favourable exchange rates bought from Italy). You can find out more about my Exan experiences here.

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