My Ducati riding physician strongly recommended a full face over 3/4 for safety reasons. Fulls offer much better protection of the face, and he referenced some study that showed injuries to the face were fairly common in accidents.
I have a full and a 3/4 (I wear rarely, just around town) the full is certainly warmer in the winter and the wind noise is less, although the latter may be more a function of the helmet style and fit.
2002 V-Star 1100 Classic
Memphis Shades Batwing Fairing
National Cycle Cruiseliner Saddlebags
7" LED Headlight with 4.5" LED Driving Lights
Engine Guard with Kuryakyn Pegs
Chubby Intake with TimB's PMS Thumbscrews