Do not worry about what Arena is doing , they are a mess of a business ! There are a lot of unhappy people who have left due to management issues especially the CFI !
Airline Academy of Australia is taking over there Building at YBAF for their Boeing/Alteon MPL training starting next year. RQAC/AAA are doing great business there at the moment, it is definatly booming.
It really depends on what sort of flying you want to do , if you are looking to do it as a career I would recommend doing it at YBAF as its a bit more realistic having to talk to some sort of ATC alot. If you are a weekend warrior YRED/YCAB are great places to learn and may well be a cheaper option.
good luck , if you need anymore info on Arena or RQAC PM me