I have used both original and the replacement version. There is a small difference in front axle "tilt" between the two - but it doesn't seem to affect driving in any way (i.e. I can't detect a difference.)
As mentioned the replacement seat and cap should be "solid" - as in no springs or other "cushion" introduced between the seat & cap at the bolts. Cushion/free play is made in the rubber ball. Meanwhile the original relies on a sleeve around each bolt AND a spring to make the "cushion" part occur between seat and cap at the bolts. Seat and cap are "solid" around the ball.
I'm not sure one has advantage over the other. Change-over from one to the other with the engine/flywheel housing in place relies on small hands/forceps/magnets - and the bolts MUST change as the replacement cap system the bolts are longer. It's fun when the bolt drops out of the forceps inside the housing.
I had difficulty particularly in putting the bolt "keeper pin" in place. Only by expanding the slot in the top of each bolt was it possible to actually put the pin in and have it pass through entirely, retain the bolts from turning, and be caught by the small cotter pin. Of course expanding the slot requires removal of the bolts, grinding the slot, and then replacing. Time consuming in iteration and much easier done with the flywheel housing removed and on a bench. (retrospection here...)
Good luck in any case!
Joe K