I would keep the osmolator...

+1
I like my controller (not Apex) but trust my osmolator's optical sensor more than float switches. I've had to clean a float lately that luckily I tested and found it to be unresponsive

I hit my optical with a toothbrush when I remember, but it's never let me down yet - 11 months so far
A spare pump wouldn't hurt, just in case ...

I have a bunch of float switches, If your interested. Hit me a PM!

BTW just as more info, I'ver had the osmolator for about 4 years and when I got it, it had those gimpy stoopid mounting arms. I upgraded to the magnetic mounts (they should be stock now), and it's awesome. The most I've done for cleaning is rubbing my finger over the lens and a fresh water flush over it... it's pretty bullet proof, I was worried about algae or other build up screwing with the refractive sensor, but not even after so many years...

The only trouble I've had with my osmolator is the optical eye. We still don't know what caused it but I think it's something to do with the way my ATS lighting. Those sensor's don't like light shining into them :(
Anyway, the optical sensor stopped working but was replaced no questions asked :)

Thanks will keep. Just need to drill hole through wall so I can feed from RO supply in next room. I have 50G sump filled half way, so I'm thinking if I fill my 20G trash can 2/3 of the way. I should still be okay if I have a ATO fail and a return pump fail at same time - right?
My tank is 120G

for 220$ you get all this with the Reef Angel controller.

One temperature probe, one ph probe, 2 ATO float switch and an a power bar with 8 controllable outlets.

If you want wifi for remotly controlling your aquarium or monitoring you add another 109$.