Look at what you have, figure out what you want it to do, find a controls contractor that will tell you their stuffs will do what you want. Pay a controls contractor to install a system, see if it does what you want it to do. Rinse & repeat as necessary.
Seriously, though. You're just a little vague in your initial post. What do you have? What isn't it doing that you want? Is it even capable of doing what you want and if so, is it just a training issue? Put in something new and different, you'll be learning that, too, and for a lot more money!
Replacing a propietary owned control system with one that is easier to use and reliable. Any suggestions?
The Niagara Framework is the most versitile and capable on the market. As for easy, that's up to the programmer, the controller can be as easy or complex as desired, and reliability in electronics isn't really an issue anymore, I have never replaced a JACE.