I wear full finger pretty much all the time. If it get too hot on a climb...I'll take them off and put them back on at the top. When it gets cold I have a pair of Specialized gloves that block the wind.

Same when I ride my mountain bikes. When I ride the full suspension...my gloves have padding on the knuckles. Hardtail...I wear leather gloves.

Its all about protecting the hands for me.