That is the MP1550 that I just ordered. I have read several posts on the sprint board over on http://www.dslreports.com/forum/sprintmb . Overall it seems to get good reviews.

I can mention if you decide on a Tekkeon myPower MP3400/MP3450 make sure you get the newest revision as they had to make a hardware change because there was a very slight voltage spike on initial power up. And if were using a Cradlepoint CTR350 MBB router and the power supply the spike could kill your router. So, the good folks at Tekkeon decided to make a change to their product in order to prevent it from happening. Even though they said it was only the CTR350 that had the problem. But, ya never know...

I was on the fence for getting an MP3450 for the router as that is the more power hungry device. But went with the MP1550 instead because of the weight/portability side of things. I grabbed the 12 eneloop's and should be good for a solid 10+ hrs...probably closer to 12 hrs of moderate to heavy use.

Did you check out what they have over at http://www.batterygeek.com ? It's a good place to find ideas of what is out there in terms of portable power.

Oh, btw, I got the MP1550 on Amazon just recently for $19.99 + like $5 shipping. So with shipping it was $25. I like it because it does have a voltage regulator which for my use, the router, it really important. I am not sure how much the NIT can absorb in terms of flaky voltage. Not sure I wanna find out either.