got this the other week, playin on live fine, but disapointed at the lack of hardcore servers!
Hardcore is a bit marmite, I have to be in the mood for it.
Sometimes i get fed up with normal mode, having to empty a complete clip into someone only for them to noscope me with a sniper rifle. So it's nice to have a more realistic damage level (or reduced health).
Other times hardcore annoys the hell out of me, as you cant see where camping f**ks are without the killcam. Also having no vehicle health bar puts me off.