The difference between the two can be quite astonishing and the amount you could save could be in the thousands over the term of the loan, so it really is worthwhile shopping around for cover rather than accepting the cover offered by your loan provider.
The quality of the product can also differ and recently the high street lenders and banks have been the target of investigations into the sector by the Financial Services Authority and the Office of Fair Trading after it was found there has been wide mis-selling of payment protection. However it is mostly the big high street names that have been found guilty of this and of course this is another excellent reason why you should go independently. So if you want the peace of mind that loan cover can provide then shop around for your cover - it's the only way to make sure you get a quality product while getting the cheapest premiums.