I will post a few thougths here.
The biggest changes I have seen since I joined in 1993 have been:
One of the most significant tactical changes has been with structural fire attack. This was brought into SACFS a few years ago now. Compartment Fire Training began in Sweden when fire fighters and scientists began to work together to understand what is happening in compartments when on fire. The result was realistic fire behaviour training - trainees get to see the phenomenon (flashover, backdraught etc.)as it happens and learns what to do.
The first Australian Fire Service to use this type of training was the Queensland Fire and Rescue Authority under the leadership of Shan Raffel, who travelled to Sweden and England to see what was being done in those countries.
Wayne Atkins From SACFS initially led the Charge bringing Compartment training into South Australia. Brett Pollini is now in charge of Built Environs Training which includes Compartment fire training.
This training is the most significant change in tactical thinking a fire fighter can undertake.
Another significant change during the last ten years has been the increasing use of aerial fire attack from both fixed wing and rotary aircraft.
Turnout Gear - From overalls and a woolen coat for BA work, to a two piece nomex kit and now to PBI Gold.
Probably the most controversial change has been the introduction of the GRN.
Also a major change probably began just over ten years ago with the introduction of AIIMS and ICS concepts. This has had it's teething problems but appears back on track.
Hope these few thoughts are helpful