If you wanna be competetive on the track a 450 is almost a must have... You can do it on a 'shee... i did... but it takes a helluva rider and it's about twice as tiring. I'd eat 5 gallons of gas one day at the track on my 'shee.... seems like I put gas in my 450 every 2 months lol.... basically:
Banshee: Good power, bad gas mileage, shitty suspension ( b/c the frame was designed by cavemen), dying breed,
450's: dime a dozen, boring(quick though), great suspension, can still race the production class, feel 1/2 as light at the 'shee in air...
Mike