*gasp* Growing Tent?!

Hullo everyone! Starting another thread!

I've seen on Ebay that apparently, there are some Mylar-lined tents that are quite cheaply sold, and I was wondering if anyone can vouch for their use? It seems that they are almost made to really be used to "vegetable" growing, but it looks quite awesome, and I'd love to get one for my appartment (to be had in a few years, maybe sooner).

So, final question:
Is this happeningly to be usefullness?

Holy crap these things exist?!?!?!?

Yup! Seems quite new too! It's apprently waterproof too, and made so that it makes it optimal for growing! I think it evens has a few places where ventilation and light related holes are smartly place.

I got the 4X4 one from Growlabs. Mine has a silver lining versus a mylar one. It's pretty slick. Has holes for cables, venting, waterproof liner, place to hang your light and fan. I'm going to eventually get a bigger one to flower and use this to veg. I was going to build one but I knew that I was eventually going to get CO2 so this made more sense.