Resale is certainty: you see the actual unit, the actual view, the actual building operations and financials, and you can close and move in on a normal timeline. What you give up is selection. In a tight building, the line you want may simply never come available.
Preconstruction is selection and modernity: first pick of floor plans, new systems under warranty, current hurricane code, and amenities designed for how buildings are used now. What you give up is time and certainty. Delivery is years out, the finished product can differ in feel from the renderings, and your deposit is committed through the construction cycle.
The decision usually turns on purpose and timeline. Need a home this year: resale. Positioning capital or planning years ahead: preconstruction deserves a look. Rangely works both sides across Miami-Dade and up to Fort Lauderdale, and will compare a specific new project honestly against what resale money buys in the same neighborhood.