I'm pretty novice with natural gut. My set up is Babolat Tonic+ 16g at mains(60 lbs) and Ashaway Liberty Synthetic 16g at crosses (57 lbs) on FXP prestige. Somtimes it feels pretty stiff, sometimes it feels very lively. I tried to see the pattern and it looks like it feels stiff on colder days with Wilson balls (not US Open ones), it feels plush on warmer days with ProPenn balls. (Current California weather is wierd with El Nina and stuff..) So my question is: Is natural gut more sensitive with weather(temperature) and other conditions than other synthetics are ?