Now they have been taken over Alliance & Leicester et al....
I moved my bank account from Abbey to Alliance & Leicester a few years ago because of Abbey's dreadful customer service. I now find that with Santander having taken over A & L, their service has also plummeted. The latest is that I have been without internet access to my A & L accounts for 5 days now- because they are having problems "migrating some accounts". I get platitudes and scripted apologies when I telephone- and still no indication of when this will be sorted. I do all my banking on-line...I live in rural Scotland and it's the best way. I shall be moving my account away from Santander as soon as I can. Be warned! All these "come to us goodies" that Santander are offering will seem as nothing if you move to them. 
July 1st 2010
It took them 8 days before I could access my account fully again. I am switching to another bank. July 6th 2010
I see from the Forum on "Money Saving Expert" that I am far from alone....
http://forums.moneysavingexpert.com/showthread.php?p=34302955#post34302955