It is a top tier WDH hitch and one of the most popular. Far better than cheaper hitches with friction bars. I do agree, the pullrite is in another class.
The Equalizer hitch is a friction based hitch just like the freeby hithces that you reference. It is 'thrown in' by dealers in our area to get the customer on the fence to make the sale. The premium hitches are not friction based and do not mitigate sway, they
control sway. They either project the pivot point to near the rear axle or they actually move the pivot point to the rear axle area usually around nine inches behind it.
I am not suggesting the Equalizer hitch is not popular, you are correct. However that does not make it a quality hitch and it is nowhere in the neighborhood of any of the three premium hitches. Perhaps why so many have Equalizer hitches is due to the dealers throwing them in to the sale.
I don't tow with a 1960's tow vehicle and I don't really want to tow with a 1960's vintage hitch and for some reason Progressive has not changed the hitch since then except for a few minor parts like the L brackets. It is an old tired stale design of hitch that was better suited for station wagons not SUV's, trucks, and vans that we have today. The hitch works poorly with modern pickup trucks, especially 250/2500 and larger as the sway function, whatever there is of it, does not work unless the spring bars are weighted. And many modern pickup trucks do not need the WD function but owners still want the sway feature. The Hensley, ProPride and PullRite all work sway independently with weight distribution--- a major feature of the premium hitches.
The only person that has to be happy with the hitch is you and if you are happy then the hitch is top tier and everything you want. Me? my eyes have been opened big time in the hitch world!