In considering any vest (gilet) or jacket, the first thing I look at is the back. IMO they must have a fully air permeable back. I have a couple of vests with mesh backs that work well. My cold weather soft-shell wind-stopper jacket back blocks no wind and I can easily blow right through it. I find this essential in helping to manage sweat. It also prevent the jacket from ballooning up when riding with the zipper partially open. Slits or vents have not done the job for me.