It depends...
If it's something which needs cooked a tad more, I'll be nice about it and ask for them to give it a bit more time.
If it's got a hair, or anything else unsavoury, I'd kick up a stink and would not eat anything else from that establishment.
On eating out, I took the plunge a couple of weeks ago and tried my steak medium rare, normally I go for well done (or in Spain, bien hecho).
It was lovely, I'm now a convert.
I went shopping for her indoors today & asked the butcher for 4 x lamb shanks for myself, Mrs Rom & both the heirs to R0m mansions.
They were cooked to perfection in tomato & basil sauce, the meat fell off the bone...I knew I married her for something.