I have only used it once but had good success, ended up buying Vision X light cannon clones for <$40 a light all in which is 1/4 of what Vision X charges and I am sure its where MRT got the lights originally. I bought them from MRT originally as clones of vision X and needed a replacement as I may have bumped something with one and could not find MRT still selling them, or in business for that matter which may not be a bad things as the customer service at the time was worse than Gobi.
It was a hassle compared to a "click and buy" off amazon with some negotiation on qualities/cost/shipping fees - a 4wk lead time and as mentioned other vendors contacting you for similar items (although it was always through e-mail not whats ap/text for me) BUT for what I needed it was perfect.
They certainly seem set up as a a wholesale type place with qualities needed although the way around this is having the order done as a "sample" but I image that only works once or twice with any given vendor before they catch on/say no.