QT or GTK for an embedded real-time display system based on Linux

We are trying to develop a real-time display system in safety critical domain. (All this is at very basic stage.) One option I have is to write my own Widgets using Ope开发者_StackOverflownGL. Other two options is to use something like GTK or QT.

QT seems easy to use and has good development tools. But I have worked on several applications in real-time domain using GTK but none in QT.

Can anyone point out to me the trade-offs involved here ?

I am settling with direct OpenGL programming for now.