The ease of use is amazing! You don't need any complex knowledge or coding experience, you just type your requirements into search bar then go through all features that suit you exactly (including pricing) which include free version as well! I would say this product has been my savior during some tough time we've had with our business.
It's an investment but once implemented everything gets better instantly - more bookings means increased revenue therefore happier customers thus making everyone happy :) There weren´t many problems when using their products since there was always someone around ready answer questions if needed even after years passed between support calls/emails sent. However i'd like to see maybe monthly data statistics available in overview page so one could have idea about performance within last month etc without having to open ticket every single week asking such question :). In order words - no issues yet - still waiting till something comes up ;).