Envid made some good points.
In comparison to MT4, cTrader is not nearly as popular. The platform is very accessible and has a good design, along with a lot of trading indicators and graphical objects. I think it's a good platform, but for some it may or may not be the right platform.
If you're into custom indicators or robots that can be a downside. I think avalibility of certain materials is just smaller compared to some of the other more popular platforms. It's also seen as difficult for beginners to use, but I think that's something that can be learned so it isn't necessarily a disadvantage.