FHSS or DSSS

[dave g]

i have 2 sanwa exzes plus radios

radio 1: has the DSSS system fitted, TM-221DS module + 441DS receiver
radio 2: has the FHSS-2 system fitted, TM-222DS module + 442DS receiver

im guessing since the model number is larger on radio 2 thats the latest one?

anyone have any idea which one should be better?
which receiver should run cooler etc and which is most likely to get interference or thermal etc?

any info appreciated

cheers
dave