I don't like dual-leaf contacts.
To each his own. I prefer them; they're much easier to insert the chips without damaging them; they essentially require accurate positioning of the pins in only one dimension, and don't demand high accuracy in that direction. The "machined pin" sockets may be more reliable in extremely rugged environments, but they seem to be designed for one-time very careful insertion of those $30 mil-spec chips; if you need that sort of ruggedness, I'd consider just soldering the chip to the board...
The $0.30 sockets should work fine. They are, after all, a brand-name socket from a "real" distributor, and not something random from a surplus dealer that's been sitting around for who knows how long under what conditions.