I'm looking at this for the first time. It holds 9 lbs of Trichlor tabs!!! I'm used to adding the tabs to my skimmer basket. What's the difference??? Can I save on tablets by using this device? Is it just a convenience device.
Putting tablets in the skimmer is not recommended unless you run the pump 24/7. They are very acidic and could damage the skimmer and equipment. The chlorinators allow you to dial in the output, you would not use any more/less to maintain the same FC level.
Of course you realize that we RARELY recommend the use of trichlor tablets due to the side-effects of rising stabilizer levels and lowering of pH and TA. See: How to Chlorinate Your Pool
We see so often that people use the pucks for a year and 2 and suddenly start to have problems ... because they do not realize that the CYA is climbing. If they work for you and you are testing your chemistry, that it great.
We saw a LOT of that this year, where the CYA was converted to ammonia and requiring a long initial SLAM to eliminate it.