For me, it comes down to two things. First, I do not want to have to charge every night since I use my watch as a silent vibrating alarm, and I track my sleep. It seems like Apple has basically overcome this hurdle, now that you can charge while you shower and basically get by.

The other issue is that I don't want to have to bring Yet Another Dongle™ every time I go away for a weekend or short business trip. Most of my trips are ≤ 4 days, so if AWs could reliably go that long (including battery degradation over time) then I'd consider getting one.

Right now, only the AWU even approaches this, and only in low-power mode. If it weren't a thousand dollars, I'd consider it. But between the low-power requirement and the pricing, it's just no contest in my book. I'm getting a new Pebble, which offers a month of battery life at 1/3 of the cost.