The ultimates are probably your best improvement, the Paul brakes would be the only other one to look at. I've tried running mini-v brakes and hated them. They grab well once they grab but unless you set the pads closer to the rim than I like brakes to be, they wouldn't work. I had to have the pads close enough that I couldn't get the noodle out without undoing the cable or deflating the tire, neither of which is a good option.