We did the heat exchanger mod to 2 800s that we ride in Whistler. I've had about 5 rides on it before my season ended. If you ride powder, it is a great permanent way to get rid of the deflector. We used to put the deflector on until we hit the alpine powder, then we would take it off to ride in the deep snow. The back and forth with the deflector got tiresome and eventually we lost some hardware from it loosening up. The new unit is lighter than the stock and lowers the weight to the ground so the machine doesn't fell as top heavy. You will have to mount scratchers though to flick snow onto the heat exchanger on the trails. Riding without the deflector in the powder is a must. In my estimation, I can climb about 25% higher without the deflector. Yes you get snow on your back but it is not that big of a deal. Peter Woosley from Kelowna sells a small deflector that apparently keeps the snow off of your back without dragging in the snow.
Overall the machine runs a little warmer. With the stock setup, my temp never got above 40'C in the powder as the heat valve bounced between the short and long loop. The heat mod lets the temp rise to about 55-60'C. It only gets above that if you don't have scratchers down on the hard pack. Overall, I am very pleased with it. It reduces overall weight, lowers the C of G and makes handling less tippy. The achilies heal would be the cooling lines within the rear suspension. After my few rides there is absolutely no wear so it probably isn't an issue; however, if one of the line ripped off how would you know until it was too late? The likelihood of one of the cooling line ripping out is pretty low though given where they are and the heat exchange itself is bomb proof so no issues there. It is a little pricey, but anyone who has had something custom modded with aluminum knows that they probably aren't making much off of these kits
I have also gone with the Chain/gear mod to replace the TLS/belt drive courtesy of CJGodden. I have had to fabricate a new aluminum cooling line that came with the neat exchanger mod as it interferred with the chain drive. It should be all good to go in a couple weeks
When I get my Hawk back in 2 weeks, I will post some photos so you will know what it all looks like...