The ladder works just fine.
What these guys are not realizing is that a DIY system puts out larger bubbles than the Hagen. Start with a bigger bubble and you won't get full dissolution by the end of the 60 inches of travel on the ladder. I suspect that in 60 inches of travel you can only get so many units of volume (what would we use, grams? cubic centimeters?) so starting with a bigger bubble just means that you have more left at the end. Been there, done that.
But, there is nothing wrong with the Hagen system. One just has to be aware of the limits of the unit, it can only dissolve so much from any size bubble, the only way to increase input is to get more bubbles, bigger bubbles is not helping.
Increasing the flow by changing the location of the ladder will help some. Reducing losses in the filter is the better thing to concentrate on. To minimize losses; add a tighter fitting lid to the tank, put in a small internal sponge filter or a canister to minimize surface turbulence.
IMO, the Hagen system is great for the 10 gallon tank. Perfect. Fool proof. Neat and tidy. Hard to beat for the money.
But, if you have 45 watts over a 10 gallon, and a powerful HOB filter, it is probably insufficient.
In my book, that is not a system failure, it is user failure. If you try to use the wrong tool for the job, don't blame the tool!