I was a customer of theirs for ten years. Luckily for me I have had gradual rather than aggressive loss so I managed to move forward without much difficulty. In short, I visited them when I was 19 (and about a Norwood 2.5). I was put on varying forms of Minoxidil and ended up paying £600 a year for that alone. Having felt uncertain about Propecia, I did not start using it until three years ago. The photos taken to track my progress were always under differant conditions (differant lighting, hair length, differant camera, etc). The biggest warning sign came when I had a tracking photo taken by them when my hair was soaking wet (in retropsect, I remember them not giving me time to even my pat my hair after a Laser treatment / wash). They then compared this with the previous photo to prompt me to buy more services. Secondly, when I raised the idea of going on Propecia (a very difficult and stressful time for me) they completely misinformed me by saying that many of their clients use Propecia for a year then switch back to Minoxidil. Do your research and make sense of that if you can!...
Suffice to say, I switched to the boots hair retention program, then finally to a private prescription by Dr Singh on the advice of Spex (look him up, even Spencer endorses him. Belgravia offer legitimate treatment, but make no mistake, they are focused on the hard sell!
The above is poor quality, but please listen. Spex is fast becoming the Spencer Kobren of the Uk! If you need help relating to anything related to hair loss I can personally say that this guy has given me direct email advice on numerous occasions FOR FREE
Hope this info helps.