I like that it has all kinds or features you need to build an application, from authentication/authorization through authorization rules up front-end validation with client side validations as well! It's easy enough so even non programmers can use this toolkit without any problems at first sight (which was important in our case). The documentation could be better though because some concepts are not clear when reading them online but only after trying out certain things yourself do they make sense; which takes time sometimes -.- But overall i really love how simple yet powerful simbiX framework makes building enterprise grade solutions very fast while still keeping your code secure by using best practices such us OAuth2 etc..