Everything is quite simple and trivial, user-friendly interfaces are comfortable to use and can be used, even a beginner without certain skills.
I feel that the MT4 server is a lot more advanced and It can support multiple trades simultaneously. It uses very little resources from your computer and it works well, even with low internet bandwidth.
MT4 is also one of the most common platforms used by traders because it is easy to trade. The positions on their time frames are located mostly at the toolbar, making it one of the easiest way to switch to different time zones.