I'm in the HE sector and have similar rules, which have annoyingly been applied recently. It is one thing I didn't realise when I was young. You see all the attractions of a pension scheme and not understand them, but they look good. Then over the years they change the rules and there is nowt you can do about it. If I go at 57 then I think it is the same, somewhere between 60-66% of the pension.
I think when I'm 80, I'm not going to be spending as much and will not be as bothered about the lower income. I'd rather go earlier and enjoy life and not worry that I'll be sitting at the age of 82 thinking I could have squeezed a few more quid out of the scheme if I had gone later, or regretting not having died yet.
@42 makes a very good point about tax. One thought was go to at 58, live off savings, bleed them dry and then claim the pension at somewhere between 60 and 62 for the higher return. That will give me up to 4 years without paying any tax, followed by paying more tax each year because of the higher amount. I'll probably be better off taking the lower amount at 58 and topping it up from savings over a longer period, paying less tax each year.