I agree with Cinderella.
TGB definitely seem to have a good brand but I really think they need to work on the business/customer service side. They still don't have a dedicated lamp for their system (although apparently one will be available soon), they have a Facebook group which is good, but the admins seem to be very selective over which posts they approve! So in my opinion it's often very biased. They had a huge problem recently when it was discovered that a lot of their bottles didn't contain 20ml as advertised! They are now selling existing stock off at reduced prices so it's probably a good time to try them out, but it doesn't exactly fill you with confidence about the company as a whole!
Personally, I'm very impressed with INK London. Have you had a look at them?