1. If you are near Cambridge why do you even mention face-to-face courses in London? There are several very reputable TEFL course providers in Cambridge. (It is after all the seat of one of the most respected and probably most well known TEFL course accreditation bodies in the world. It is highly unlikely that anyone would be running dodgy CELTA courses right under their noses.)
2. The website you reference is not important. What is important is the course provider. The course provider in this case is ITTT aka TEFL International et al. and like certain other course providers they have many mirror websites that are not under their name. In such cases, you should ask yourself "Why?"
3. The other vitally important issue is accreditation. The referenced accreditation in the case you mention is "Board of Academic Advisors (BOAA)". Most Google searches for "Board of Academic Advisors" or "BOAA" point back to the TEFL site you mention or its mirrors or some other TEFL sites. Google does not seem to point to an organization called Board of Academic Advisors (BOAA). In such cases, you should ask yourself "Why?" (And even if you did find a site for "Board of Academic Advisors" you would be well advised to do your usual due diligence.)
You may find the following helpful:http://www.tefl.net/teacher-training/faq.htm