Several people I know have/had a BBVA loan at some point in the past and all of them seem to have very similar views on the company and loan as a whole.
Firstly, they seem to be quite willing to lend the money as long as you have the equity in your UK house. They will only accept up to 60% of the unmortgaged value of a property so in most cases (and I stress MOST) they will not be able to repossess your/family's houses.
Secondly they are not the best as a banking institution - especially comparable to UK Banks such as Halifax or HSBC. They have two people who sort out and manage loans/accounts for CTC, OAA and FTE so as you can imagine they have a lot on their plates. Replies often take days and answers are given to questions that weren't asked. You have to open a current account to go with the loan but I don't know of anyone who has used it - as what you can do with it is very prohibitive.
Thirdly, if you are planning on getting one of these loans always start your application early, and always read the small print or you may be in for a surprise. It's not unknown for people to have taken about 8/9 months to get a loan sorted and it can have a big impact on course start dates etc. Always get a solicitor to go over the contracts once you get them, and if you find something they don't like then ask to change it - as it can be done!
For most people this is the only way to get onto an integrated course and it does work. They are a stable bank with huge divisions in Spain and South America. Just make sure you start early!
Hope this helps.