The panther 570 would be the better buy for the money with less mileage. Both engines are very reliable and also similar in power output. The only major differences is that the panther is fan cooled and the pantera is liquid cooled. The pantera is also 'loaded' up more with saddle seats, passenger handwarmers, reverse, etc. If you will be doing alot of 2-up riding and lots of mileage the more comfortable pantera may be worth the extra money but if not I would go with the Panther.