I'm pretty sure the ps versus pdf is just the way the print job is handed to the driver that converts it to whatever the printer actually needs.
Certainly my Brother HL-2040 doesn't print postscript of any kind natively, it needs HP PCL. My Epson Artisan doesn't even use a native driver from the fedora repos, it is from some place that produced a 3rd party driver for epson. It has worked unchanged through several releases (including fedora 19).
ok. Thank-you Tom. - Bill.