I have the Tunze ATO on my 150g, the nice thing about it is the optical sensor keeps the water level very consistent for the skimmer (the sump isn't baffled properly). On my Picotope I use a Reef Keeper Lite controller and programmed an aqualifter to run for 2.5 minutes every day. Eventually I'd like to get the SL2 module and some float switches but for right now the timing method works well enough.
Back when I bought the Tunze reef controllers weren't as affordable as they are now. The Tunze is a nice setup but if it weren't for the optical sensor and not wanting to spend time trying to dial in a new ATO on the system I would have sold it by now and let the controller take care of it.
Since setting up my pico I'm a really big fan of the RKL for $100. I know it's more expensive than some of the ATO solutions but you get a pretty complex light controller, thermometer, thermostat for heaters, chillers and fans, other timers, fail safes, and headroom for future expansion. I already had my aqualifter but I think I only paid ~$15 for it? I guess it depends on what people are looking to do but if I were to be doing a brand new setup for a friend the $120ish for a controller and aqualifter becomes affordable pretty quickly.