As a general rule - if you are going for a unit, the closer you are to rail and shops the higher CG and rental return, however, this is not the case for ALL suburbs. Some good quality DD should reveal everything you need to know.
I suggest that you do proper on the ground DD and interview the agents and then do figures to figure out which pocket you are comfortable with and stacks up for you financially.
Sometimes going for a not so great pocket stacks up better financially if you need to balance your outgoing cash flow rather than chasing higher capital growth. Depends on your overall strategy.
Regards
Lisa