I have had the Reef Keeper Lite Plus, Apex JR, & Full Apex. My vote is for Full Apex or Apex Gold Package, as the Apex is the most user friendly and has the best software and support. Not to mention, the modules, parts, etc... are the easiest to find locally. If you plan on monitoring PH, ORP, Etc.., go ahead and buy the Plus or Gold package and save a little dough.
Can't comment on Reef Angel+, would like to get my hands on one though to give it a go. The Reef Angel is not as pretty and neat as the Apex, but it does have cool modules and attachments. It seems like it would be the best controller for DIY LED control, as it has PWM dimming support.
In the end though, IMO, the Apex beats the socks off the Reef Keeper systems. Apex has way better software, great hardware, and a large user community to turn to when you have questions.