Has anyone tried bridging loans? In case mortgage

In case mortgage not approved in time.

I am going to a house auction next week, the completion time of payment is 6 weeks. I am a bit worried about the mortgage won't be in place in time, thus I am considering using some bridging loan services provided by AuctionFinance or Acceptances. The loan time ranges from 1 month to 1 year, the rate is around 3% above 3Month Libor rate plus 1% processing fee (which is around 5.5% in total). They can make decisions very quickly, normally 1 day to 1 week.

Has anyone used such services before? Any reviews/comments? Any pitfalls?

Thanks very much indeed.