Just bought this 2010 3 weeks ago and it came with Road 4 GTs, I have put about 2000 miles on them and all is good even great traction when turning the power on from the Schnitz Racing flashed ECU. So I went to Cycle Gear Moto Bash yesterday in Sacramento and won a free set of my choice Michelin tires So I ask are the Road 5 GT an improvement over the Road 4 GT ?
Nobody knows yet, the 5GT is still not available yet. I love my PR4 GT, so if you need to get now, and they are free, then you can't go wrong with PR4 GT. I get incredible life with them, they handle very well, stick well, and have great wet traction. If you free thing lasts for several more months, you could just wait and see; it sounds like you have lots of life yet. No sense in wasting money!