Was debating on getting the DynoJet PC V or the Juice Box. Found the Juice Box Pro for about $250 brand new, so decided to go that route. Just got it installed today (after removing my flies) and I couldn't be happier. The JB Pro can hold up to 10 different fuel maps and you can change maps "on the fly" with a small phillips head screwdriver. The unit came with a zero map, a stock exhaust map and a map for the Two Brothers slip-on. I was able to locate (with the help of a board member)a DynoJet map for Two Brothers slip-on/flies out and imported it in to the Juice Box with no issues. Just got back from a test ride and all I can say is WOW!!!!! I had an ATRE on the bike before, but removed it when I pulled the flies. The ATRE does not compare with actual fly removal and the right map. I'm a happy camper