Opinion on ARM mbed

I’m currently working on a my Thesis where we are evaluating/comparing four lightweight IoT OS, and we will implement the two most promising ones on a use case provided by a company that develop IoT products. We are looking at mBed, RIOT, Contiki and Zephyr and right now it looks like mBed and RIOT are best suited for the use case implementation. I can get back to you guys with my results when I’m done if you are interested.