After using those systems for many years in an industrial setting I would say they are excellent. I probably used 3 different manufactures over the years but in the end we stayed with flow rite.
The way that things can go wrong is that they can overfill or under fill. If they over fill you will see liquid and a big mess so just keep an eye on things. If they under fill you will know it when you have a capacity issue as one cell or link in the chain will be bone dry. I would say the best thing is to have a very clean water supply so no grains of sand or other crud get in.
I know this sounds bad but if you did one thing as a sort of insurance policy, I think I would do one system check to be sure they are working. After x number of weeks or months it may be worth while to pull each one and be sure they are watering. That way if one wasn't filling you would catch it before any damage is done. That one cell would be low but not empty.
My experience with flow rite would say you dont need to do this but no system is perfect.
We put the systems on and forgot about it until the battery came back smoking hot. They did fail but we were in the worst of conditions.
The one and only good thing about manual watering is that you are 100% certain that every cell is at the proper level.
We would have meetings and they would say whats the deal with all the battery problems. I would tell them go through the fleet and pull every fill valve to insure proper filling. No way, the mechanics didn't want to do it, they wanted to sit on their rears on over time and do anything. But again, we were in bad conditions. We ran tap water in a 30 year old factory. Even with that the battery itself would usually run for 8 yr or more before the lease was up on them. Some people think the battery will drop dead instantly if it's not distilled. I do use distilled myself though.
So ....right now, do you have a record or a good idea in your head of the time frame that your batteries need water? If so, this knowledge will let you do a system check at about the right time so as to not go below the plates.
If that system check proves ok then just keep everything clean and corrosion free and forget about the water system.
