I am -1 on the front and +2 on the rear and I find it perfect. It is not for everyone though, so you may want to get a chain with an extra link or two in it and get both a standard size and -1 front sprockets so you can swap them about. I use a Healtech speedo healer and it is perfect. I had it on my Z1000 and swapped it to my ZX10R by just buying the loom as they are separate, so you can swap it from bike to bike. With standard gearing the speedo is about 5% fast, for standard front +2 rear, the correction factor on mine is 9.6% and with the -1 front as well is 14.9%. The Healtech calculator just needs you to put in your standard gearing and tyre size and new gearing and tyre size and gives you the correction factor. You can store two correction factors in the unit so if you change the front sprocket, it takes a few seconds to change the speedo healer. I taped my mobile phone to the bike with a GPS speedo program running and the speedo was reading spot on compared to the GPS speedo.
If you want to see what differncve the gearing will make to the speed of the bike, try using this. You can put in standard plus two other choices and compare the three.
http://www.gearingcommander.com/I had also bought a Healtech XTRE to fit, but with the lower gearing, I don't find the lower power setting in the lower gears an issue and haven't bothered to fit it.
