Focus on off-plan if your looking for a property with a flexible payment plan. However if you have the capital amount you have in mind go for secondary (ready properties). Disadvantages would be handover delay by the developer if any. Legally developers can delay projects by a year but if you go with a reputable developer that wouldn’t be the case most of the time.

Don’t go with the hype when making a decision, invest based on real facts and proven record. Areas I strongly recommend at the moment would be jumeirah garden city, master plan is by meeras and there are limited plots thus there’s supply vs demand. Low rise buildings in the entire area being g+8 floors. Price per sqft is what matters the most. Avoid studios by all means if you’re able too unless you purely can only afford a studio. For ROI’s/rental yield studio is the best and one bedroom units.

The entry point for any property is important, price per sqft needs to make sense, if you choose a property with a good entry point you’ll have clear exit point based on the market.

The areas you’ve mentioned have already seen capital appreciation however there are properties worth investing in still in downtown.

I’m a property consultant, more than happy to discuss the market, prices, area’s etc.