For the last year or so, there are more 5p tables and fewer 7p tables. At 5p tables, players generally agree there is no talking. At 7p tables we generally agree anything can be said.
Here are a few thoughts on the subject:
1. When sharing knowledge, it must be open to everyone at the table. Any form of private message is cheating.
2. In order to cooperate with discussion, diggers must also reveal info and weaknesses (where the gold is, who to break, etc.)
3. Open discussion helps diggers more than saboteurs.
4. 5p games, (with max sabs), favors the diggers slightly, so sharing information makes the teams even more unbalanced.
5. 7p games, (with max sabs), favors the saboteurs slightly, so sharing information makes the teams more balanced.
6. The biggest benefit to playing with 5 players is shorter games, and shorter turns.
7. The biggest benefit to 7 player games is richer strategy, and learning interesting tips through discussion.
8. Since there are fewer tables with open discussion now, experts can't share knowledge, and so the skill level on the site has dropped.
9. By default, open discussion is allowed, but players may agree to no talking, and the game can be enjoyed either way.