I had mine for almost a year through various weather conditions: cold, hot, heavy rain, you name it. And the adhesive still held strong. The black never faded even though I parked the car outside for most of that time. I like the look and the clean back glass was a big bonus for me. There was also no loss of radio reception either, if you're concerned about that.
If you like how they look, get 'em!
I tried getting mine off my old car at the repair lot but couldn't figure out how to get the hatch open without power. I'd like to get another set, but can't justify buying another set at full price.