hosts column always "?"
 

Why does the "Connections" tab "Hosts" column always show "?" rather than the number of hosts connected to a particular server?

Mainly because it is a hangover from old methods of working. You are a client connecting to ultrapeers (previously all clients were equal). The ultrapeer is shielding you from some of the network overhead - part of this shielding means that you don't get told the number of hosts.

If you were to run as an ultrapeer (you really need a broadband connection) then you would see a hosts count there.

Mark