“Off-plan or resale: which would you buy?”

Off-plan usually means 20 to 25% down, monthly payments through a build of four years or so, then a balloon payment at the end. If your plans change you can often sell the contract. The risk is that you're buying a promise, so stick to reputable developers. It's rare now for a building not to be finished; more often some promised features don't turn out as described.

With resale you can walk around it and talk to the people who live there, but you need all the money up front.

Either way, the building matters more than the unit. The management company, the facilities and how the money is spent decide what your condo is worth in ten years.