The non-premium WD Hitches has a longer lever arm (moment) working on the TV's tail
HA & Pro 'project' the pivot point to reduce the 'apparent' lever arm length
Pullrite is mechanically or actually moves the pivot point just behind the TV's
axle. So the lever arm is in actuality very short. Down side is that this system
does reduce ground clearance on 'some' to 'most' TVs.
Pullrite ball to coupler is fixed. Meaning it does NOT pivot there. As if the
tongue is lengthened (actually it is) all the way to the 'new' pivot point just
behind the TV axle
I'd stick with the Pullrite, as long is it is fitted correctly to your TV and
has the correct bar rating.