The first consideration is power source. You will need a large air compressor (big tank) to feed a pneumatic die grinder for any degree of duty cycle... running vs not running. If you have the compressor, then not an issue. Mind you, an air tool will use *a lot* (almost 10X!!) more energy overall than an equivalent electric tool. The other thing I consider is weight. power-to-weight on a pneumatic tool will be better than an other tool. air tool is lighter than corded is lighter than cordless. If you are going to be doing a lot of work... as in hours of effort, you can't beat an air tool. Especially with the newer lightweight hoses. That said, they are generally a lot louder than anything else, so ear protection is a must. If you have the air, and you don't need the portability, and your tooling (cutters) will fit, go for pneumatic. I run an older CP 3119-15 and it's a beast. I have a large Makita electric, and for longer jobs I prefers the CP any day.

Edit: I took a look at your cutting tool. If you are working wood, I'd say an 11A tool is probably overkill. 1/4" shaft is light tooling. The other advantage of air tools is cost... you can probably pick up a few for the cost of a single electric. Very handy to have 2 or 3 grinders at hand with different tooling in each.