One of MV drawbacks is the C# Client renderer , honestly it sucks, very dated and laggie,
it lags for no reason in some spots
found way too many disappointments on the client side. :-(
the only thing I still messing with MV is because the server, server is good. but the client makes you look away unfortunately.
only wish MV had client alternatives.
I am seriously looking at unity3d and smartfox server lately and am very impressed with unity rendering DX11 and tools + smartfox server.
so if you arre familiar with C# and java, unity + smartfox can be a great upgrade from MV + you will feel at home coming from MV.
cuz rendering and tool wise is 1000% jump of improvements and looks like smartfox server is proven networking tech. so you may feel like a great upgrade.