Back to the topic - HSBC here too, only had it for a couple of years though - I used to put everything through my personal account (I'm a sole trader, sell my services not goods, so not that many transactions). But when I asked the Co-op if I could have a second current account to use for business, they said no, you must have a proper business account for that, and by the way you should not be putting business transactions through your personal account.
At the time, HSBC won for fee-free period and lowest charges thereafter (£5). I haven't had any problems and my banking is all quite straightforward, so I can't say what their customer service is like.