I don't know much about this outfit, but personally I would consider 2 things - (1) a secured loan means that if things go wrong you could lose your home and (2) I would much prefer to use a bank or building society, they tend to be alot more open about the terms and conditions. There are loan rates of around 5% with some of them. Have you looked at www.moneyextra.com ?
You can see the best deals on the market, and compare to see which would be best for you.
I'm always wary of companies that do a lot of expensive advertising - if it sounds too good to be true, it probably IS!
All the best.