It is worth it, you just have to try it...
For all those complaining about "how easy can it really be?" You need to consider the actual use of the device. If you've never actually used one, then you are not really in a position to compare, are you?
I have three of these devices in my house, due to having multiple zones and HVAC units. Having had the experience of using a Nest for several years in my previous house, I am a convert. I too once thought it was just a gimmick, until I actually installed and used one.
It truly is easy to use and convenient. You may not want to admit it, but part of the reason you tend to "set and forget" your current timer/beige box at a single temperature and never change it is because it is so Byzantine and clunky to change. It is just easier to find a compromising temperature that you can live with and be done with it.
With the Nest, I just spin the wheel and watch the rather large number change. I don't have to think in schedules, program it or anything. It will remember that I like it at, say, 70F during the afternoon and 62F at night for sleeping (Fahrenheit, because I'm a yank); that my high-traffic areas should maintain a more constant temperature than my bedroom, which is only occupied at night; that during summer I want cooler temperatures, while warmer temperatures are welcomed during winter; etc. I don't think about it, I just dial it in as I feel, and it will just learn it. If my mood changes, I can adjust it as necessary, and if the pattern persists, it learns that too. It's brilliant.
It's hard to convey the convenience to someone who has never experienced anything other than an arcane beige box. It reminds me of trying to explain Netflix back in 2005 to my father: "Why do I want to rent DVDs online??? I can just drive to Blockbuster whenever I feel like watching a movie..." My response was always, "I thought the same thing, but then I tried it and now, I can't imagine having to walk into a video store to stare at the rack of discs for several hours to pick a movie!!!"
Really, the Nest thermostat is a very convenience and well designed bit of kit. Your mileage may vary, but please understand that things can be different -- and sometimes even better -- from what you are just accustomed to.