Last some brands and styles of scokets really
didn't stand the
test of time. I have a few NS* boards I've desocketed and soldered
the chips directly in becuase of that.
I normally replace such sockets with good turned-pin (I think you call
them machined-pin) ones. I've yet to have had a contact failure on one of
those.
If the ICs are rare/likely to need to be removed in the future (EPROMS,
etc) then I'd want to keep them in sockets.
-tony