I'm in the market for window tinting and am not finding much useful info on the 'net relative to differences between the manu's and their products. I have three options I'm mulling in terms of brand and I can't tell how to differentiate them. The options are GeoShields's Ceramic, Lumar AT, or SunTek's Carbon or HP film. The prices for the latter two manu's are about the same (~$120ish) while the GeoShields is offered for 180.

Anybody know anything about this stuff or have recommendations for someone who might? My target is improved heat rejection with glare being secondary. The spec numbers on the manu's web pages don't seem to be apples-to-apples, unfortunately.