I have never seen (or heard of) the 'fixed pin' setup as is in the picture in your link where the pin stays in place in the piston and the rod rotates on it (learn something every day
).
I have only seen where the wrist pin is slightly larger than the wrist pin bore in the rod for a 'press' or 'shrink' fit. Between the two I prefer the 'shrink' fit (where you chill the pin and heat the rod) as it is more secure (in my mind anyway) and you are less likely to have a problem with galling as you assemble it.
The other two setups shown in the picture I have seen, the 'semi floating' type in various Flatheads, the 'floating' setup I have seen in Aircraft, VW's (air and liquid cooled), and Motorcycle engines stock.
If I am building an engine for performance (as opposed to a stock overhaul) I prefer the floating pin for ease of assembly, it also reduces the chance of the pin seizing in the piston on initial start up (rare, but I know a few people that have had it happen with pressed pins, they are all careful about using lots of assembly lube and oil).
FWIW a piston pin can be set to 'float' in a rod without a bushing. The Motorcycle engines I have worked on (FJ 1200 Yamaha, in line 4, Air Cooled) did not use a bushing in their rods. But you have to leave twice the clearance between the pin and rod when it's steel on steel. I guess that's fine, if you want that, I just prefer not to run steel on steel. You also need a way for the oil to get to the clearance between the pin and rod.
Hope that helps.
