I joined A&L to get the £100. So far they have opened my accounts in the wrong order which prevented me from getting my 'new customer' perks, sent me the wrong online log in details, argued with me about whether I have the wrong online log in details, and failed to pay the correct interest on my account at any point in the 3 months since the account opened.
If you value your free time and sanity, don't touch Santander with a barge pole.