4 years and got an arrow in the knee!
After years of flawless cooperation (got very good credit ratting) they decided to cut my overdraft short in Octover / November 2011 (mind xmass closing in) without sending me a letter. Did shopping as usual and was hit with fees for going beyond the overdraft limit (as it went down from £500 > £100). After few phone calls and visits to branch, they decided to refund me over £100 and reinstated my overdraft to previous limit. So, had a bad experience but did recover. However, next year they cut the overdraft short again leaving me with low cash supply just before xmass.. not happy with them, this is not what I'm expecting from a bank! Moved to FirstDirect - so far so good, can't tell bad word.