Not familiar with that one, but I can tell you from previous research, all of the so called "drop in replacements" for R12 are problematic. Most are either flamable or toxic to beat all, and some may leak through the hoses on R12 systems. Many of them are simply different blends of the R134-A stuff that gets put into new cars and retrofits.
There are a couple of independant testing outfits with web sites that give stats, ingredients and other info on freon replacement products. I put the links to the EPA web pages below. Do your homework carefully, AC is not a place to mess around.
Ahydrocarbon containing replacement refigerants are suspect as they are likely to be flamable. Looks like this product hasn't hit the EPA test yet, but they are obviously impressed with themselves and make lots of claims as to safety, compatibility and performance.
Don't know if it's TGTBT, but you know what they say...

Ben Vahl

http://www.epa.gov/Ozone/snap/refrigerants/lists/mvacs.html

http://www.epa.gov/Ozone/snap/refrigerants/lists/unaccept.html