Hi Gemma,
I finished my course last year December and have never touched another brand anymore!
The educators of Odyssey are very skilled (at least here in the Netherlands, I do not have experience abroad) and are keeping themselves up to date with developments e.g. in this branch.
The ONS products are very nice to work with and I have absolutely no problem with my allergy while working with this brand. When using another brand, I mostly get an allergic reaction to the liquid, but Odyssey is free of any reaction - at least for me.
I am indeed very pleased with the Odyssey products and will not use any other in my salon.
Please let us know how you like your course!
K.rgds,
Mariska