I've been using it for many years now - mainly because we are an advertising agency that has used 3rd party providers in our past but also because of its incredible support team! There is nothing i dislike about KF at this point although if there were something better out than them right under my nose then they would be way down near number 1 (which isn't good!).
Great product with great people behind the scenes supporting your business needs without any hiccups alongtheway which you don;t always get from other vendors or even yourself when things aren't working correctly internally either due too much stress/workload etc.. We have had no issues nor bugs reported by customers who use kickfire daily throughout Europe & USA so far since 2013!! It does what every single customer wants us all do day after today:-).