I'm in the same situation .. already have a deposit down but might step off if there's no slipper. Its nice to be have one of the first RCs here but the value will pretty much tank on the non slipper ones once the next batch is released with them.
This seems to be a good review. Touched on a few issues that I didn't know existed with the RC390 like plastic touching the ground on heavy leans. Plus 2016 version might come with slipper clutch. I have a deposit on my 2015 RC390 right now but might actually cancel and wait for 2016 if...