I haven't used one Bird, but at $399, they seem a little pricey. One could easily get a new gas mower and an electric weed eater for half that.
Plus 'starts effortlessly with a push of a button'. Who wants that . . . sounds too easy! /forums/images/graemlins/crazy.gif
In all seriousness, the trimming part of the mower looks like it would be kind of difficult to use. Perhaps more work than a hand-held. Are there other electric mowers out there to look at?
One last thought, when my wife and I were newly married we had a very small yard (think trailer lot). I bought a new reel mower for about $50 and mowed with it for two years. It gave a great cut and my neighbors were always borrowing it. When we moved to a new home with a larger lot (70'x100') it was really too small, although I occasionally mowed the front yard with it. Had to watch for sticks though, as it was easy to jam. Almost zero maintanence though, never had to sharpen or adjust anything, but did spray it from time to time with WD-40