I trained with Billion Dollar Brows Essex last year and the training was absolutely amazing, I have a little home salon and Billion Dollar Brows is very popular.
The only things that I didn't like was:
That the training was with warm wax and it was a dreadfully cheap wax (i thought I'd be using Australian bodycare hot wax as that's who distributes the bdb products) and I use high quality wax and hot wax for Brows and felt like I'd gone back in time to my old college days of dreadful wax but I was confident enough with the amazing training to then go home and practice to use the technique with my hot wax.
The professional only online shop drives me nuts you add one item and it changes the quantities to several and takes ages for the pages to refresh, and you have to order a huge order to get free postage. At the moment I only need one thing the brow gel is so tiny and gets used up very quickly and because postage is so high it's not worth it!! I also don't have the money for lots of stock or the space to store products so can't retail so if someone wants to order one item then the postage is so high it's not worth it for me.
Apart from those things the technique was great to learn as it focuses on creating a defined brow with a natural shape for the face , I have many clients that return regularly and the makeup products are lovely. The trainer was lovely and you send case studies and the best thing was she is very thorough and only passes you when you create the perfect brows so lots of case studies needed I think I did about 8 case studies and two were sent to Billion Dollar Brows for approval.
Hope this helps x