This harness is unbelievably light, I know we all know that but, its worth mentioning again because it really is insane.
Its really a great harness for ski mountaineering. It does not have actual gear loops so if you only need it for rappelling which is more common in skimo than actually climbing its perfect. You can wear it from the car because you forget its there.
To use it rock climbing you need to make a few adjustments on how you carry your rack. The two small gear loops, aka the little nylon loop on each side cant really hold a full rack, not because of weight but, because its too small. I have been taking a non locking biner and using that as the actual gear loop. Then you also have your two extra non-lockers on the harness should you need them. I still dont put my protection or rack of slings on there. Usually hanging my belay device and anchoring materials. So the big change that was needed is you pretty much have to use a shoulder sling to carry the rack.
I use two shoulder slings, on one all the protection, on the second, I rack my slings. There are some products out there that make this type of racking easier, specifically the Metolius Big Wall Gear Sling which we dont sell yet! Soon though. This way does make transferring the rack a bit easier but, thats just me, everyone has their own way. Just wanted to point out that you wont be putting your alpine rack on this harness.
You could also tie some accessory cord to each loop going around your back to get a loop which is easier to hang gear on. I tried hanging directly on the harness and that didnt work well.
It should be noted that some of the Alp Race competitors are not fully CE and UIAA certified. This harness, though its light, can take a fall just like any other harness out there double, or triple its weight. Is it comfortable to fall or hang in as other harness, no. Its comfortable to hang or rappel in when its layered over a jacket or two but, sometimes I just wear it over a t-shirt and I can feel it but, that's expected.
I've scraped this through sharp rock, and beat the crap out of it just like every other harness I have owned. It shows no more or less wear than anything else which is impressive considering its weight.
Camp USA also came out with a slightly more robust version of this, with actual gear loops. http://www.backcountry.com/camp-usa-flash-harness? . Its double the weight but, you get the four gear loops, normal tie in's and belay loop, plus its a bit more comfortable. The guys over at Camp USA climb in the Flash full time pretty much.
33-34" waist and the XL fits a little too big when I dont have layers under it, I might grab another one and get the large as I will be able to cinch it down when not wearing it over a bunch of jackets.