It is great. I have two one is a older first gen as I like to say the first day it came out and then my second one. A third one is going to be ordered once my frag tank gets farther along.
Both have been spot on and working great. I would purchase again without any hesitation.
Both are set to adaptive mode and keeping my alkalinity within .1.
It took a while to dial it in to keep it to .1. What I learned was I needed to really know my daily consumption and then use the 80 percent rule.
When I turned on adaptive mode I reduced my dosage to 80 percent of the current value and then tweaked it.
It has never overdosed, never caused me any issues or grief, just time and patience to dial it in. I did monitor both tanks for 6 months before even turning on adaptive mode.
I had two issues with the older model, both documented on the forums. I had to replace the inner tubing and remove a filter.
PH probe maintenance is I calibrate it every 6 months

. I had to replace two of the older cover models on the doser, which was covered by warranty.
You will not be disappointed.
Forgot to also add I dose three part on the one system. This also is in adaptive mode, and has kept Mag, and Ca spot on. I manually check those once a month, but since I have dosing containers and see them daily I just see if they are all at the same level.
On the other I am using a calcium reactor.
Hope this answer