Anyone Using External Batteries from BatteryGeek?

I've been looking at various solutions to powering my MBP and eee. I had a couple of spare batteries for my MacBook which are now pretty worthless, I would like one power source for multiple devices, and I'd love a solution that doesn't require me to put my laptop(s) into sleep mode just to change power supplies, so I'm thinking seriously about getting an external battery pack . . .

After a bunch of Googling, the only provider that came up regularly as providing an external battery that works with Apples was Battery Geek. In particular I've been looking at their 130Wh Portable Power Station which should provide at least an additional 4-5 hours of battery life for a MacBook Pro and could also be used to power/charge an eee.

There was one bad review, but on the whole the reviews seem pretty good. And there doesn't seem to be much in the way of competition that I could find.

I like the idea of a single power source for all of my devices that I can continue to use with different devices, something that doesn't require entering sleep to change (I always switch batteries in the MacBook at around 10% to make sure I don't lose work, so that's 10% of the capacity of each battery wasted) and something that could even be used to charge most devices allowing me to leave some of my chargers at home when I travel. (The only downside is that it won't charge a Mac – it would just power it).

The model I want will be coming out on April 14th, so I could get it just in time for the start of conference season.

What do you think? Any advice/opinions/thoughts/experiences? As always, any input much appreciated.