The pros are extra power! the negatives are you need to retune the sled unless its EFI.
The test!
EFI-remove your air filter and go for a short ride. If you feal the extra power than installing a K$N will help.
carbs- remove air filters and go for a short ride, You may need to adjust(richen) the carbs as the air flow rate will have changed.
If you add a high flow air filter to a carb equipt sled it can cause a lean burn condition from lack of fuel!
More air + more fuel = more power
more air= lean burn
more fuel= rich mixer
EFI adjusts itself- carbs dont!
91 polaris indy 650rxl