I have processed about 8 deer, an elk and one antelope. Most of the meat was made into hamburger, but the past couple years I started making a lot of slim-jim or beef sticks. For those I find a shooter workers better after grinding. But you asked about grinders. I use the old school hand crank model. Porker? it's also sold at Cabelas. It works like a champ and goes through meat pretty quickly. Not as fast as a large electric, but gets the job done in a reasonable amount of time and a heck of a lot cheaper. I couldn't justify the price of an electric and really didnt want another appliance to store. I already have a smoker, dehydrator or to many other appliances. If someone is ever considering a hand grinder my only recommendation is to buy a bigger one. They come in all sizes (volume) and the bigger ones go faster because you can put more in it. They last forever. I've had mine for 10 years and no real sign of wear.
I also tried the Kitchen Aid attachment. We have a professional grade mixer for baking and it has a strong motor that can be used for all kinds special tasks. One of the attachments is a grinder. The grinder attachment is a total piece of junk. The main grinding cutter was made of hard plastic! It just didn't cut the meat or push it through fast enough. I went back to the hand grinder...it was faster. I know that's not what you asked about, but thought I would mention it in case others read this thread.