I run it in one of my cars and am about to convert another. The pro's and con's as I understand them to be are:
Con's
1) Heat transfer isn't quite as good with the Evans glycol coolant as for water/antifreeze/coolant. Water has the best heat transfer properties. It is normal for you engine to run a couple of degrees hotter with the waterless coolant, but that is unlikely to be a problem in any engine, and in some, it may actually help.
2) It's expensive, however over time, should be cheaper as it lasts so long, especially if you factor in the cost savings associated with 1) and 3) below
Pro's
1) The biggest one IMO is that it is completely electrically non conductive unlike normal water/antifreeze. Some cars, especially classics with a mix of metals in the engine and the odd electrical gremlin/short circuit can suffer from electrolytic/galvanic corrosion.
2) It is non toxic. Untold damage has already been done to the environment by people improperly disposing of traditional antifreeze mix, which is horrendously dangerous and a small amount if it gets into a water body such as a river or lake can cause a huge amount of damage.
3) Higher boiling point (160 degrees?). Goodbye steam pockets and cracked aluminium heads caused by trapped air in the system.
4) You can drain it during water pump changes and put it back in the engine, so it can last the lifetime of the engine, but you may need to top it up a little depending on how well sealed your system is and evaporation from the radiator overflow tank.