It really depends upon who the guy is. On most men, groaning and telling me that what I'm doing is how he likes it is good. I really get turned on when they tell me they are getting close to cumming and yes I really like guys who grunt loudly when they cum.
As far as dirty talk goes it has to depend upon the guy and if it fits his personality. If he is Mr. Cleancut, conservative, proper type of guy, who doesn't swear and speaks eloquently than all of a sudden he starts talking dirty it seems out of character to me. It's not believable and then is a turn-off.
On the other hand if he is a rough around the edges type then it would be most appropriate.
I don't want to hear any crap back about this one - but I used to have sex with these black guys and for reason they could say the dirtiest stuff, call me all sorts of names, degrade me and it was this really intense turn on. It was all sort of animalistic type black taboo thing, hard to explain but it was awesome.