I can usually get Oracle db patch sets applied in about 15 minutes. I only do single-instance, no rolling-RAC. I can't complain about the time it takes an experienced DBA to apply.
I can, however, complain when Oracle divides everything up into two sets of patches and forces you to run OPatch twice (as they did in the last set). I can also complain about all the GRANTs that I have to remember to run so the patch doesn't barf. The patch process should be as simple as "yum update."
I can also bitterly complain about how terrible the encryption tools are for TNS. It is *so much easier* to bolt an stunnel instance in front of the listener and never, ever, ever use an Oracle wallet - and safer too, since stunnel can sink itself into a chroot().
Oracle databases - wonderful software, until it's not.