I really liked how easy it was to use through our internal tools, as well its user friendly interface for customers who are not familiar with ML models or Tensorflow yet! It's hard sometimes when customer needs new features added into their model quickly without much development time but we have some dedicated developers working regularly around this area so everything is good now :) The free version has limited number of users in one project which can be quite limiting if you plan using more than few products at once (I used only two).
But since they offer unlimited projects during trial phase, i didn't find any problem there actually ;) Support team works great - even though support tickets goes unanswered very rarely :), always available via phone call / chat etc., fast response times from them too!!