I've heard (and the one Max I've driven w/ stg 7) have a pretty touchy throttle and the street manners are somewhat compromised. It's tougher to drive smoothly. The one bike I drove ran well, but after idling in traffic for a while it started to run really rough and would sometimes stall when you touched the gas. Didn't like to get too hot.
Carb kits are easy to install especially with the help of the excellent carb rebuild tutorials in the carb section. And unless it's a shop that's familiar with the Vmax (like PCW) chances are it won't be well tuned, or not as good as it could be.
hmmmm....negatives.....
-The full system will probably be illegally loud, so if you happen to find a bike checkpoint(at least in NY these pop up around Americade time), you may get a slip inviting you to donate to the local coffers
-It will be faster, so you're more likely to "accidentally" speed
-It will add virtually nothing to the resale value of the bike.