The Spidi, like my Cycleport Ultra II Kevlar, has a detachable waterproof liner worn INSIDE the protective shell. This is a great concept. My Aerostich, while a great piece of gear in every other way, was too hot for humid Tennessee summers. Notice Aerostich is built in Minnesota. With the separate liner concept, the non-waterproof outer shell can be much more breathable than Aerostich type gear. It's as if the entire suit surface is one big vent. My Cycleport is as protective as Aerostich (or better) and almost as cool as mesh. Waterproofing with this separate garment is superior, since the outer zippers & vents do not have to be waterproof.
The liners are also great waterproof rain gear worn off the bike.
I wear the waterproof liners up to about 85deg., then it is nice to have the option to remove them. These types of gaments can be a bit more fiddly with the extra liner, but to me, the payoff in hot weather is worth it.
The nice thing about the Aerostich is that, if you can stand the heat, you are always wearing (almost) waterproof gear.
The Spidi also has waterproof outer pockets, which the Cycleport lacks. This could be a great suit.
Check out
www.motoport.com. They offer several very breathable fabrics at different price levels. I have been happy with my gear, and it is made in U.S.A.
K-Dog