I have heard some critics saying that DHA city is an overly ambitious project and it may not see completion.
To judge if something is going to be a worthwhile investment you would need to establish the return that your investment will achieve in your given timeframe. Return is determined by the price and the prospect for appreciation.
Personally I don't see any attraction in the price and I don't see or know when the scheme would be completed, I also don't know the location of the scheme therefore I don't think there is any attraction in it in the short term however in the long term anything is possible.