You stop tripping over uneven pavers and finally have a flat spot for the grill that doesn't sink into the mud. Pouring a concrete patio takes about three to five days of actual work, but getting it on the calendar takes some planning. Early spring is the sweet spot to book local masons before their summer schedules fill up and prices creep higher.
You need to call at least three different contractors for quotes before you sign anything. Prices swing wildly for the exact same slab, and you want to see who communicates well and shows up when they say they will.
That intro window is a strict deadline, not free money, so treat the monthly payment like a utility bill. If you still carry a balance when the 15 months are up, interest charges will kick in on whatever is left over.