I have flown with three of the various types - API, Van's, and Bell. We also own one of the Aviationtech "Bell Clones", but haven't flown it yet - I expect there will be no difference between it and the Bell (noticeable from the cockpit).
Van's, Vince's, Bell and AviationTech all use the same "Knuckle" on the end of the tail wheel spring - you don't have to change it. They all also use the same steering arm and axle bolt. The API has it's own shaft diameter (slightly less than Van's), so you have to use their knuckle and steering arms - as well as a different axle, which means different bearings. If you buy that one, you have to match drill the two holes to the spring for the mounting bolts. Not a big Deal, but it takes an hour (and careful measurement).
The API, Bell, and AviationTech all look similar - rounded forks that are really pretty looking and have the greatest ground clearance - the wheel will hit ANYTHING before the fork will. Vince's and Van's are more like heavy "sheet" wrapped around to the axles. Vince's has far better ground clearance than Van's.
When I changed to the API on the Valkyrie, it was pretty much the only easily available option. if I were to change it out today, I'd go with the Bell or AviationTech for commonality purposes with the rest of the "fleet". It is a pain to need a different wheel and steering arm. Not that they have to be changed all that often, but I like commonality. I haven't used Vince's, but have read nothing but good things about it.
While there are different heights involved, my personal experience is that an inch or two of tail height disappears if you squirm in your seat just a tad, or sit differently, or the cushions are cold rather than hot. Minor irregularities in a turf runway will matter more than which wheel you have - unless you get one of those monster tundra tailwheels of course....
That's about all my experience with the different wheels - I have a few hundred hours with each, and honestly, they all fly about the same (in my opinion) within the normal variations of RV'ating.
Paul