I hate to give this kind of an answer, but it's just the truth:

ProWizard does everything differently from any of our other editors. Because of that, basically every feature about it is going to be considered better by some installers and worse by others.

If I were to describe the basic difference, it would be this way: ProWizard is designed to arrive at a particular UI structure with your client's gear, preferences, and desired graphical style in place. You don't have to learn as much, but you don't get as much flexibility. MX-Editor is designed to let installers decide exactly what the end result should be for each of their clients. There may be a longer learning curve, but the payoff is greater flexibility in the end result. Programming may be faster or slower, depending on the skill of the programmer and the desired end result.

That's why I say the MX-810 isn't a "little brother." It's just designed for a different set of installer needs.