Robin2:
I have never used 433 MHz wireless so you will have to wait for someone else to help with that. AFAIK it is a lot less sophisticated than an nRF24, but, as you say, it does operate in a different frequency band.You have not answered my request for "details of how often data needs to transfer from a slave to the master". That is important whatever system you use.
...R
Well in Epee the system needs to be able to lock out an opponent in 50ms. So I'll say that this needs to happen in non more than 1ms. Personally I don't mind if the master box buzzes 5ms too late after a touch as long as the master box knows it's buzzing 5ms too late. If I can do some extra work with time stamping and verification and making sure everything is very well synced then I don't mind the box being 5ms late on buzzing. Ideally not.
Hope that answers the question.