Whoever told you that was just wrong.
Timmies are cut on a CNC from extrusions, except for Dragons, which are cut from billet aluminum. This makes them infitesimally better, if you squint a little.
They are good because they are simple, reliable, and sort of solid. They have less reciprocating mass than a Spyder, although they are laid out about the same. They are autococker barrel threaded, so everyone already has barrels for them. They have always used break-beam eyes, and those have always worked pretty well.
The problems with them is that tolerances in the older ones were not as strict as one might wish, and they have suffered from quality control issues on occasion. They rattle when you shake them and feel cheap, but once they are gassed up and ready to play with, they straight rip.