I bought one of the first PST Leathermans (what, twenty or twenty five years ago?) and just bought the Charge TTi. Side by side, I cannot tell a quality difference. The "old" tools used stock removal (aka grinding) to make all the parts - new Leathermans use investment casting for many parts. Investment casting is a process widely used in industry, and Ruger has always investment cast their rifle & pistol parts.
To me, the TTi feels much better in hand than the PST. The Ti handles are rounded at the edge, the grip surfaces are textured, etc. The locking mechanism for the tools is superb, and the knife blades use liner locks (just as do BenchMade & Chris Reeves, and other top quality knives).
If you look closely at the pliers, the casting mold parting line is clearly visible (open the tool & look down at the base of the plier). These complex parts could certainly be ground from the solid, and would probably add another $30-$40 to the cost of the tool. And the function would be no better.
Don't make 'em like they used to? No they don't ... now Leatherman uses titanium & S30V