Waldo: My choice would be Monarch. The flight is direct on the A330 and legroom in Premium cabin is more than adequate.
MAN/LGW/MLE is a one stop as is MAN/DXB/MLE.
I'd much rather spend my connecting time in Emirates T3 in DXB than LGW. Connecting time spent in DXB is minimal.
The EK service is far superior over Monarch