LiMe is right, unless you care about drag racing it's not worth it!!

extending the swing arm changes the dynamics of the bike drastically. makes them harder to turn, and reduces turn radius and also changes the suspension dynamics too!

if your just looking to stop wheelies yea just learn how to ride correctly!! however if your trying to launch at 9k rpms then sure go get a extended swing arm. but have fun trying to make turns

 

a longer wheelbase will also feel more stable at higher speeds

but if you do want to hit some twisties it won't lean in very quickly