I was resistant for years, thinking it was ridiculous to spend that much money on it. I finally broke down a few months ago and bought one from DFS.
Talk about luxury. It's so nice to be able to do a few swipes with it, wipe off any algae, and be done...without getting wet, without having to wash my hands, and without getting annoyed having to reach into my tank and scrub around.
Since then I've acquired two more with different craigslist tank purchases.