The apex is pretty darn flexible. Reefkeeper is making ground with their new product, archon. It shows allot of promise, BlueZReef has one.
If you are looking for a safe investment in a crazy flexible, well established, good resale controller, then you cannot go wrong with apex.
Start with a jr and add on over time, not a bad way to go.
You will love it.
I have allot more peace when away from the tank due to it. APEX saved me a few times already from things I may not have noticed without it.