Just got my GT MAT delivered today. I ordered it on 11-12-12 and got it today 11-16-12.
i bought the 10sq ft of coverage 50mil kit for $24.99 SHIPPED
GTMAT Automotive Sound Deadener 10 sq ft 50 MIL & 80MIL installation pack

whats in the box?
1-3ftx3ft roll of 50mil GT Mat (mine actually measured more like 3ftx3.5ft)

1-roller
1-GT Mat tape measure
1-free sample piece of 80mil
Instructions, 2 GTMAT stickers and $5off next purchase coupons
Upon opening the box i noticed how much it DIDNT smell like tar/asphalt. A definite plus when installing inside of vehicle. There is slight odor but nothing to worry about. I think its just from being locked up in the box for 4 days.
I got the 50mil cause it was cheaper and it would be easier imo to use. Easier to put behind panels and easier to mold.
in the pics on the website the 50mil seemed like more than enough but in person not so much. Still not disappointed with the product yet. They included a free sample of their 80mil. see the comparo below

80mil on top
50mil below
I plan to do my trunk floor, trunk lid and under the hood. I will be cutting the roll into pieces to make it go farther and will do some other areas with any left over pieces. All that coverage for $25 shipped($40 shipped if u choose the 80mil) is not bad at all imo

I will be buying another set in the near future to do the interior floor and doors
will be back with review of installation when its done