What Mach 1.5 said.

In addition, ensuring the rear of the piston is supported means that it moves in a straighter line as the spring unravels, and the tuner can tighten the tolerances between piston, liner, top hat/guides and spring, reducing frictional energy and torque effects, and smoothing the shot cycle.

Yes, terms like “Lazaglide” were good advertising, and, yes, the cost/benefit ratio of this sort of custom work was always questionable compared to a “spit and polish” service/tune, but it is hard to argue against Messrs Pope, Hancock, Welham, etc.

It’s also notable that the AA TX and “Walther” LGU/LGV do the same in factory form, and (setting aside some irrelevant issues around the durability of the “Walther’s” trigger group) are generally regarded as exceptionally nice-shooting out of the box.