Keep it coming guys, be nice if this was a sticky, lotta good info here. Nothing like personal experiences to fully inform one of whats out there, whats ****, and what works well.
Well, Radman, since you asked for it, I live in the Eastern Washington desert, and ride in a lot of different temperatures during the summer. My riding gear includes a 2 piece Aerostitch Roadcrafter II suit, Firstgear Kilimanjaro, Kilimanjaro Air, and MeshTex jackets. The only thing I can add to the other comments about the Roadcrafter is that it is really easy to put on and take off. I have heard that if you put ice cubes in the pockets they last longer than you would think and provide some pretty good cooling.
The Kilimanjaro has a pretty good venting system but you have to take the jacket off to open the vents properly. It is really in its element in cold and rainy weather but the pockets and vents are sealed so well they are difficult to use. The Kili Air is probably the most versatile jacket I have ever owned. It is about 70 percent mesh and comes with a very high quality insulated, waterproof, and breathable liner and probably has a comfort range from 50 to 100 degrees. The only downside is that I have to carry a light weight rain jacket when I take the Kili Air because even though the liner would probably keep me dry, the jacket would get pretty heavy if I had to ride in the rain all day. If the weather is not expected to be under 60 degrees, I leave the Kili liner home and take a much lighter Joe Rocket liner.
The MeshTex is even cooler than the Kili Air because it is lighter and flows more air. It also comes in lighter colors (the Kili Air's mesh is black). I think the MeshTex is actually cooler than riding in a T-shirt because it blocks the sun's radiant heat and when used with an evaporative vest can make triple digit temperatures bearable. The MeshTex does not have anywhere near the protection of the other jackets but I saw someone slide 40 yards in one and didn't have a scratch (under the jacket). The MeshTex was pretty chewed up in places but it did its job.
I have yet to find a suitable pair of pants for hot weather. I have a set of Firstgear HT Overpants, Teknic mesh pants, and Joe Rocket mesh pants. I usually take the Aerostitch pants off when the temperatures get above 85 degrees, likewise for the HT Overpants. I have not been impressed with the mesh pants, they just do not seem to flow enough air (except the hot air off the engine) to help that much and since they are all black in color they seem to absorb heat more than get rid of it. My Teknic pants are next to worthless, they do not have enough mesh to cool anything. The Joe Rocket mesh pants have lots of mesh but it is a "large" mesh that would snag and rip in a slide and you really are supposed to wear them as overpants so they provide additional protection rather than cooling. I was going to try the Firstgear mesh overpants but on a recent trip my riding partner couldn't tolerate the Firstgear mesh overpants in the heat any longer than I could tolerate the HT Overpants. So far, the coolest pants I have found for riding in the heat are light colored denim -- which is not what you want to be wearing in a slide. On the way back from WFO-4 I met a rider wearing Aerostitch Darian lightweight pants with a Roadcrafter II top and he said it was a good combination in the heat but those pants cost $300. I might try some Joe Rocket dragging jeans next, their actual protection is subject to debate but it has to be better than straight denim.
What do I take on a trip when it could be both cool (its usually cool in the mornings in the West) and hot? The Kili Air jacket with liner, a lightweight breathable nylon rain suit jacket that I bought at Costco for $30, Joe Rocket Sahara Vest, denim jeans, and the Firstgear HT Overpants (rain pants not required since those pants are totally waterproof). If it was going to be really hot (over 100 degrees) with very little cool weather, I would take the MeshTex jacket and the Joe Rocket mesh pants. In either case, I will probably end up wearing only denim jeans once it gets hot since I think heat stroke is a bigger risk (and more likely to happen) than a slide.
