I'm loving the cooler weather. The S3 seems to run so much better when it's cool out. I bought my bike in the spring and was loving the power, then summer rolled around I really noticed a drop off in performance. Now with fall here the bike runs like the bike I fell in love with again and I can't wait to jump on it every chance I get. Is it just a 955 thing or are the 1050's the same way? I don't remember my America being this temperature sensitive.
It just means your bike is running a little rich. When it's cooler the air is more dense and helps burn that fuel and makes HP. It's just the opposite in the summer. You might want to lean it up in the summer and go back to your original settings in the winter.
I can really tell a difference in performance (with both of my bikes) between day and night riding. If i'm riding back from somewhere and it's 10/11pm it runs much better and feels a lot faster than it did earlier in the day, engines prefer cold air.
Can't tell the difference between seasons though to be honest (other than bikes feel really fast again after a long winter without riding at all!)
Just took my S3 for a spin today and it ran insane. I didn't get much of a chance to ride it in the heat since the weather went to crap as soon as I bought it. I did notice a little extra grunt to it. The darn wheel just wouldn't stay down.