Needing a remap is just an indication that a part is doing its job - flowing more air. If you don't need a remap then the air in/out of the engine hasn't changed much, so power hasn't changed much. There's no gettting around the fact increasing power means increasing air
and fuel.
I've run several different bolt-ons in the last year or so. I had my biked mapped with the California Speed Four tune (map #10164) when I first installed an aftermarket can. It made a difference for me. I'm currently running the stock exhaust with that tune and it works just fine too. No aftermarket can did good things to the fueling, which is part of why I always ended up back at stock.
You can get a baffle insert that would go in the mid-pipe to provide the restriction of the stock system, but let you run an open can. You could also experiment a little with it for best sound/throttle response. You could also go for a SuperTrapp with the tunable disc system (talk to Fury about that

).
I feel the draw to the bling of an aftermarket can, but every time I give in to temptation I find that it just doesn't
work as well as stock...
Detailed description of my exhaust experiences below:
I've had:
--Devil SB2 (too loud, but beautiful and sounded sweet)
--Triumph Carbon race can (also too loud, too big visually, but sounded sweet)
--A chopped and shortened Kawi ZX6-R stock can (not too loud, but wierd places in the RPM range resonated and annoyed me, look didn't flow with the bike). For the time being I'm back to the stock can (for the third time! :razz: ).
My friendly UPS Santy Claus should be delivering something to alleviate that in the next few days. :-D