I subscribed to their site at a cost of 73 a year, but beware they just keep taking your money, every year, without any prior notification, no reminders, and once they have your money they will not refund it even if you advise them you want to cancel.
If you do want to cancel you have to write to them, and send it in the post! they do not accept emails, and there is no option to cancel on the actual website.
Really bad customer service they are only after your money.
Remember this is an online business but you they make really difficult to cancel, doesent this tell you something.
However, there are a couple of differences - the Premium members are positively identified by a credit card, and consequently behaviour and maturity level tends to be much higher than some of the free board's users.
Membership of the free board also confers the ability to set threads limited to the premium board, or moderated threads shared between the premium and free boards (for more information about this my review of the free board).
Originally, the PBB was a thriving, but slower, more measured, somewhat staid version of the FBB (and a bit cliquey, too - a lot of the members there had known each other for years from the old ESI boards).
This all changed when a large number (half? more?) of the PBB members decamped en masse to be founder members of MoneyAM. At a stroke, the PBB membership dropped below critical mass and it became much less vital (the MoneyAM equivalent, the Traders BB was even worse, to be honest. Also, a lot of the cliqueyness decamped to MoneyAM as well)
Slowly, over the months that followed, the PBB has built up the participation level, until the advent of the shared, moderated threads has completely revitalised it. Now, there are real benefits to being a member of the PBB, and the abilty to eliminate the morons from threads has seen an increasing number of FBB threads migrating to the premium board.
At the moment, the momentum of the board is increasing, and it's in the best state that his been for a long time, possibly ever.
There has always been active participation by the AdvFN staff on this board, and this remains the case, meaning that feature requests, problems and complaints can all be aired easily (and sometimes acted on).
Of all the boards around, this is the only one I would (and do) pay for - I feel it's worth the £5 / month