The 500 is a very good boat, easy to handle. Simple rigging, no daggerboard, just skegs. This makes for a very streamlined boat with simple controls.
A F16 will be faster, will go upwind better, and will be way way way lighter. If you race you want a F16.
I'm sceptical with the ability to right a nacra 500 alone unaided in all conditions however. I think a righting pole might be necessary.