I've just resigned from the IPA as they've increased the subscription to £11. I've been a member for 6 or 7 years (joined at the same time as BALPA) and in that time they were great for keeping an ear to the ground and getting employment information.
They had a flagging out campaign a while back but that sums up 6 years of membership. They try hard but have no "clout" whatsoever. I saw £11 as unneccessary expenditure seeing as I'm in a BALPA recognised company.
BALPA subs work out about £19 after tax relief and for that I get an awful lot more. I also pay through BALPA Financial Services for a Loss of Licence policy which they offer.
Nothing is perfect but some are more perfect than others