Winter is off the road at the moment due to a twisted crank
They are very different to each other, the winter has a much higher cruising speed, much more torque, handles worse and uses loads of fuel, the GP handles lovely, its quite economical but I don't trust it enough yet to ride it flat out.
The GP is much easier to ride around town than the winter just due to the state of tune on the winter and how rich I run it with very retarded ignition, its hard work compared to the GP. I had to stop ridding the winter while I was testing the GT kit in the GP just because every time I rode the GP after the winter it felt sluggish even though there is only around 4 bhp difference in them but the higher torque on the winter makes a huge difference when ridding distances.
They are both as comfortable as each other to sit on all day.
If I was honest I would say I would rather ride the winter but after it only averaged 26mpg going to modra this year I had settled on riding the GP and after killing the crank in the winter on the M6 toll a couple of weeks ago I have no other option but to ride the GP until I find another good 62 x 115 crank.