I have the unifilter/Leo Vince and accelerator combination and I have no real complaints. I run the LV with the baffle in. I tried it without and the fuel economy was absolutely incredible ... 10% better so even though I didn't really like the extra noise I thought I would put up with it for the better economy and range. Probably it was fortunate that after the first tank of fuel the ECM adjusted itself to take into account not having a baffle and the fuel economy returned to normal. I put the baffle back in.
I like the combination of the LV, unifilter and accelerator. I put the unifilter in first and apart from being washable it did produce a better more responsive throttle. The LV is lighter and being carbon fibre doesn't get hot, it also produced a bit more top end power and it sounds nice but not loud with the baffle in. The accelerator module (or booster plug!) just stops things getting too lean and really smooths out the throttle response and give the impression of more bottom end power. My 800 now has great smooth linear throttle response off the bottom, good torque and enough top end.
This is the type of throttle response that KTM 990 riders would probably sell their grandmother for ... but don't tell them, most of them wouldn't believe you and the others will just be jealous!