Also to consider when mapping out your career path - if you have any choice in it, of course!
Under current Australian rules you could get 1500 hours PIC in a Baron, then theoretically start command line training on an A-380 and after 100 or so hours of ICUS become a Captain. Totally improbable, of course, but legal.
The old terms 'low capacity' and 'high capacity' will disappear from the regulations and you will have Part 135 and 121 for little transport aircraft and bigger transport aircraft respectively.
Under the new regime, say you work your way up to a command in Part 135 on something like a Saab and log 5000 genuine PIC hours. When you go Part 121 - even with the same carrier - you will most likely have to do at least 500 hours of Part 121 operating experience (i.e. as F/O) before being eligible for a command. Then most likely 100 hours ICUS during left seat line training.
Or you could simply start in the RHS of a Part 121 type.
Either way, times are going full circle to the day soon when it could take 20 years for someone starting as a cadet pilot in one of our major carriers to get a command on a heavy aircraft.
Building time in GA does of course have many merits, but in future improving one's chances of an early command won't be one of them.