I like how simple it is to use, no complex tools or software are required for this platform! The UI/UX of their website can be improved in some cases but overall great experience with them so far!! They offer free trial which gives me confidence that they will deliver what we need (a solid API-level integration). We're using these guys as an addition tool when writing acceptance tests against our product's web application interface - mainly because there was nothing else out here at all really good enough yet available via SaaS model :) I like how easy it is to use, and that we can have multiple apps tested at once without too much hassle. It's also very well documented which makes for great support from our team of testers when needed. There are no downsides as far as I know. We've been using this product since around 2013 so there might be some improvements in newer versions but they haven't had any major changes. The main benefit is being able to run tests across different platforms (iOS/Android) with ease.