I am biased because I have sites in Belmore however, I do think Canterbury is the best bang for your buck in Sydney if your looking at purchasing OTP.
Canterbury is just on the border of Dullwich Hill and in time Canterbury will be considered an 'inner city' suburb.
You can still secure 2 bed apartments OTP for around that $650k mark while if you look else where you cannot find anything at that price point. I mean, new projects in Hurstville are selling 2 beds 'starting from $780,000'.
You need to secure something close to the train line so that can have strong cashflow.
If your looking for OTP Canterbury is good, however I am bearish on Sydney as a whole because the OTP prices in general are far too apart from existing stock and rents.