Re:
I get to see both sides from the inside – I work for the CWU but strangely, I had to join the GMB (who are the union representing the staff working for the CWU) in order to protect myself. You'd think working for a union was cushy gig. Far from it.
Somehow, I've managed to survive working at the CWU for 12 years but during that time, have had to request the help of the GMB on far far too many occasions. The CWU's previous general secretary (Billy Hayes) told me himself that I didn't deserve to be admitted into the union's staff pension scheme when I applied for it. This from a man who never had to contribute to his own pension scheme with the CWU, who had a grace and favour house as well as his own, had his mortgage paid, and, accrued so much 'overtime' that he paid himself around £18k. In the end, I had to go with the government's national NEST scheme.
You'd also think being the member of a union would protect you too. My partner used to work in the NHS but ran into problems with a line manager after some illness. Unison, the biggest union in the UK, wouldn't respond to any of her calls for support and advise – the branch rep only supported management grades. Instead, Unison emailed through a substantial form which asked up front if the member could afford to pay towards Unison making legal representations. In the end, she just gave up and quit her job.
A lot of people working in politics (doesn't matter what colour) are careerists and it's quite an incestuous world (again, it doesn't matter what colour the politics). There's a lot of careerists moving through the hierarchy of unions, from branch reps to organisers to the various levels of officials up to president or general secretary. I'd concur with some of KDM's points around this aspect. However, as in any organisation or company, you do get those who are genuinely committed, do care and do try to make a difference.
Generally, as Brocklanders says, unions are a force for good. Despite the restrictions of legislation on unions, some are now in the process of repositioning themselves as wider political campaign groups, harnessing both their members' support and the wider community to change things for the better, though some of this also helps to sustain the union. I'd say if you work for a company or organisation with union recognition, it's better to be in a union. It's a no brainer.
But, above all, my advise to anyone is to try and keep a diary and document everything you can – dates, times, conversations, incidents, how you felt, emails and correspondence. Yes, it's difficult to devote time and energy to but documented evidence is the best defence you can be equipped with if you're ever sucked into a dispute.