There has been a post about this in the past. Really is a long discussion. But the short version is they both work great. The ems uses three servos to run the swashplate, and the mms uses one servo to control the swashplate.The ems uses less linkages and bellcranks than mechanical. You can go on and on, there are some sites on this matter were you could really be nick picky. The most important rule for a new flyer is to see what the other guyes in your club are flying. If they are flying the same ship as you, see what setup they have. If you do not live anyware near a club like I do that can be tough. So like most of us we are using the EMS. Me myself I am using EMS, and feel comfortable with it. If you have a radio that supports EMS you might want to consider that route. Any of us guyes can help you set it up along the way just ask. I hope this helps.