It is user-friendly and sounds a great alternative for prototyping. The customer service is very good too.
It's a very cost-efficient option that comes with amazing depth and variety. The interface is also very user friendly and simple to use.
The good things in there are so many, but most of all I liked how easy is to provide lots of info into one exercise and make sure you always complete tasks when needed.
It "kills" itself sometimes somehow. Poor functionality/elements for designing/prototyping for responsive designs.
The customizability of this product is very limited. We're not able to customize the design of premade components and their theme is very limited.
My biggest concerne is with performance. It is painfully slow to work with and that is the main reason we abandoned it in my consultancy.