As someone who doses, I figured I would chime in here. I have been maintaining my tanks by dosing for better than two years now and have been quite happy with it. I dose not to save money, but for the ease and for the consistent results that can be achieved with this method. By dosing at a steady pace via peristaltic pumps I have been able to maintain rock solid levels in our system without incident up to this point.
I run peristaltic pumps 24 hours a day continuously dosing 2 part. I mix my two part at concentrations that keep my levels right where I want them if I dose very close to (just under) the rate of evaporation in our system. This way, I kill two birds with one stone, keeping my levels just where I want them, and eliminating the need for additional top off devices. With this system, there is no need to worry about pumps sticking on and flooding my tank or throwing my levels way out of whack, because the pumps are always on anyway. I don't need to dose Kalk (a common point of failure and cause of tank crashes) in my top-off to maintain PH, my PH stays right where I want it. I don't need to worry about probes and solenoids, I don't need to count bubbles or drips, I just fill up my barrels, and walk away, done. Once per month, I mix new 2 part, that's it. I dosed our 240 (an SPS dominated reef), and found no issues. I didn't find build-up to be excessive on my pumps, or other equipment, I think the slow steady rate of dosing is to thank for this, perhaps shorter bursts of more concentrated 2 part might cause this problem for some people. I have now been dosing our 560 with equal success.
In a nutshell, I have been very happy with this system, it has served me well. If you ask me, I would rather run this system than set up a reactor and it's associated equipment any day, not because it is cheaper, but because it is simple, effective, and safe, end of story. I for one am bummed at these recent developments, unless I can come up with another answer for the calcium end of things, I will have to move to a reactor, something I would rather not do.