Disclaimer on wind management, I'm 6'4", 275 lbs, where a big well padded aerostitch jacket and a full face or modular helmet. That presents a fair amount of frontal area.
As a bike moves through the air it has to move the air somewhere else. If the bike has a large enough frontal area to move the wind around you, you are likely a happy rider from a wind management perspective, unless it's too hot. Think large touring bike, and imagine the wind being pushed out of the way. :-)
For smaller bikes like the TR650 and the KLR the frontal area of the bike, for many riders, is insufficient to move the air around the rider. In this scenario, there are two things I have observed. On a bike like the KLR, the VStrom, etc., the design tries to get the air around the rider with windshields, fairings etc. But the air typically does not make it. So you end up living in a pile of turbulent air, often more than you would if you had no fairing at all. On the KLR, for me, it was pretty rough air. The VStrom was the worst air ever stock.
On the TR650 I think the key difference is they accepted the fact that they would not be able to move the air out of the way, so they just let it come by where it naturally lands. For me, this results in a lot of air on the top of my thighs, and nice clean air at my head. I like the clean air on my head. The air on my thighs and low on my body does not create fatigue like wind higher up on your body does, that makes a big difference on longer days.
I've ridden the TR650 for a couple of 6+ hour days on pavement, and it doesn't fatigue me. I wanted off the KLR after an hour. The air was rough, there was a lot of it, and it was hitting me right in the chest.
I have seen a couple, but I've seen them resolved by getting the air out of the cooling system. I think the hottest it's been since I owned my Strada has been about 70, so I don't have an opinion yet.