I have the apex lite. I love it. I ended up buying another energy bar. At the time I didn't want to spend all the money on the full apex. I guess maybe I should've. wouldn't really need the other probes. I only use one ph and temp probe.
The Apex is a sound investment. Which model you need depends on your tank and what you're running. I have the Apex Jr on my Solana, but I don't need the lights to be controlled (I have a Radion) and only need a few outlets.. I'm thinking about buying another energy bar, but I haven't pulled the trigger yet.