I use the VarioS-2 with controller, but I believe they are about the same in- terms of the interface, just different sizes.
I've been running it for 4 months. Its very quiet and had all the included plumbing parts to connect it to my aquarium. (The only thing I can hear run on my aquarium is my Radion Fan.) It runs at 70% intensity and it consumes about 18W, so fairly efficient too.
I have only touched the included controller once or twice because it is connected to my Apex. So I can't comment much on how effective the onboard controller is. You need to get the ice cap controller cable to connect your Apex to your VarioS controller if thats what you are looking to do. I turn it down to a trickle during feed modes and maintenance mode....my first DC pump, I like it.