I'm with Paddy on this.
Definitely happy to chat to receptionists / girls, but I don't go there to chat to the other mp.nets.
As for the idea that someone wouldn't say that they've seen you, that relies upon the idea that other mp.nets are equally discreet. It's already been established on here that some guys talk about their chatting with their mates, so if one of them recognises you, good luck with keeping it a secret!
That's not my main reason for not chatting to other mp.nets, though. It would just seem weird:
"Alright mate?"
"All right."
"Nice weather."
"Yeah, hot for June."
"Tell me about it. Who are you fucking today?"
"I'm doing Sharon."
"Nice. Had her last month. I'm in for Gabby today."
Sorry, just weird to me!