Works GT trimmer and edger

I was watching an infomercial for this and it does sound intriguing. I like the fact that it's adjustable to trim under decks and low objects, and it automatically feeds the string without having to bang it on the ground to feed it. However, I'm still holding tight to my credit card in hopes someone has some experience with this before I jump.

Has anyone had experience with this? I'm really wanting to know if it's worth the money and how long does it run on one battery charge. We groom almost 8 acres. We have a gas weed eater and it works okay, but is a little hard to start and the string gets tangled all the time if you don't re-thread it carefully.

Here's the link to the product: http://www.worxyardtools.com/garden-tools/cordless-grass-trimmer.html?source=gg-branded-trimmer&gclid=CKHgmOablpQCFQECGgod8S8BtQ