Factors

Consider 5 to 10 years from now. Location factor can be infrastructure (MRT, LRT etc), good school (within 1km), parents home, work place. Unlike good view can be blocked by new development, location will never change therefore it is the most valuable factor for a flat. The flat value near MRT will almost well-defended from erosion (so far).

Next, floor plan, direction and floor height will never change too. For fengshui believers, direction and floor plan is essential point. High floor is usually more windy and quiet. Ashes from offering burning sometimes can reach floor 8 of normal HDB flat. Corner unit is more quiet and has more piracy than corridor unit. Do consider number of units per floor and per flat. Remember that more occupants share infrastructure and produce more noise.

Echo from expressway can reach some floor and direction. Direct evening sun can be really hot. Usual north facing unit is more windy due to monsoon wind. Furnishing is bonus but don't take it as part of the requirement.

Next to comment is the floor plan.