Although house prices are seeing significant rises at the moment, Inner city apartment prices are likely to take some time to grow as stated in this article - Sydney, Melbourne inner-city apartment price recovery still a way off (smh.com.au).
The significant supply of inner city units in Sydney and Melbourne is a major factor in this. The vacancy rates for units in these areas have also been very high recently, causing landlords to accept significantly reduced rents.
This is something for landlords and potential investors to be mindful of as they consider different options.