The samples I ordered were terrific. Very sturdy fabric and better quality than I have seen anywhere else.
In the end, I just couldn't justify the money. Instead, I sewed old sheets together in double or triple layers and made curtains that covered the entire window. They block the light very well and keep the rooms much, much cooler in the summer. My dd's room is on the south/west side of the house, so it was very, very hot.
Jo Anne fabrics has "insulating" window shade material available by the yard. It should be easy to make some roller blinds!
Some other ideas:
* outside shades (awning type) on south facing windows
* trees in the right place for shade
* when it is time to replace the roof, go for a reflective metal roof. (may reduce homeowners insurance costs in fire-prone areas)
We got solar screens that go on the outside. They were pricey, but they've made a big difference. The downside is they darken the house so we have to take them down in the winter--kind of a pain. If you'd rather have fabric Country Curtains has a bunch of solar ones that look good, and I've seen them at JC Penney.