Want more power? Do what I did: get a Kerker or the Buell performance pipe -- there´s about 6hp and 7lb torque added. If you drop in the Buell performance cams, you can goose the Blast up to about 45-46hp and about 50lbs torque. Not a blazing fast speed machine, but you´ll still get 55mph around town.
I´ve put 10k miles on mine in 2 years. Not until recently did she need any real work. At 7k the rocker box gasket went (as it does on all Blasts) and at about 10k, the head gasket needed changing. Her main enemy is heat -- air cooled, there´s nowhere for the oil to go when you really push these bikes; they tend to dump some into the air filter area. Still, if you change the oil regularly and keep an eye out for the occasional oil leak, they´re practically bullet-proof, maintenance wise.