So, after listening, reading, asking questions, and especially with the help of our best resident Vic mechanic, I've done 4 mods that will give you the best seat of the pants feel in performance improvement at the lowest cost.
It's a combination of 4 things and if any of these 4 things are missing from the equation; there will be much less improvement.
1. Replace air filter with a high flow washable filter. The Victory one is fine. I used a modified K&N. Cost of this mod could be anywhere between free and $60 depending on where you get the filter.
2. Remove foam strip under tank for air intake. Cost: Zero.
3. Disconnect O2 sensors at the disconnect located about 6" back from the O2 sensors. Cost: zero.
4. Drill a 1-1/8" hole in the plate approximately 18" from the outer end of the pipe with a hole saw and extension's made for the hole saw. Cost: zero if you already have the tools or can borrow them. About $30 if you have to buy them like I did (from Lowes). Very important to make sure the hole saw and extensions are secured with the set screws in the extension or you will leave your hole saw in the muffler forever. Don't ask me how I know.
This allows the motor to breathe out and makes the exhaust a touch louder unless you really honk on it; then it barks somewhat but still not what I would consider loud.
If your engine grenades; hook up the sensors before having it towed to the dealer.
Total cost: Somewhere between $0 and $100 depending on where you might buy the filter and tools if need be.
I haven't put the bike on a dyno yet but my butt dyno tells me it has got to be at least 5 hp and maybe 8 ft lbs of tq more. It rides with 2 people on it as good as when one person was on it when stock.
I was going to make a cam change a high priority but after doing these simple things; I think it'll be just fine the way it is now.
Also, if you do everything but disconnect the sensors, it'll most likely be running too lean unless you use a fuel controller like the Lloydz or PC-V.
Edit: Warr110r posted a good thread on how he did the pipes and some vid's to compare the pipes.
Modified XC Exhaust