Shimano has Dura Ace Di2 and now the more affordable Ultegra Di2 gruppos out. Campagnolo has been experimenting with their electronic shift group on pro race teams for years and is supposedly very close to release, and now there are rumors of SRAM also working on an electronic shifting system.

The reviews I've read and watched on Di2 say it's pretty much a 'game changer'. Here is an example of a Di2 review:

http://vimeo.com/6744095

And another:
http://www.youtube.com/watch?v=WJXKCoxMLnU


So my question is, does anyone have any real world hands on experience with an electronic shift system? I'm not jumping on the bandwagon just yet, but I'm very interested in electronic shifting once the price falls below $1k, and would love to hear your opinions.