The master socket simply has a few more components in it to ensure that the line is properly terminated and has a bit of electrical spike protection. If you want to indulge in a bit of paranoia, make sure that your expensive stuff is connected either to the master socket or sockets further down the line away from the incoming bit of wire
The components are mainly for BT's benefit rather than the customer. If you need better protection from things like lightning strikes etc., you can get quite cheap combined surge protected mains distribution socket blocks with a telephone surge protection filter fitted as well (Comet, B&Q, Homebase, Woolies etc.). Haven't tried one of those with BB yet though.
Cheers
ST