I build homes in Orlando, Fl and use 7/16 osb. I've used 1/2 3-ply,4-ply and 5/8 plywood in the past. The plywood doesn't seem to hold up as well in the rain ( it will delaminate) as osb. The price difference is also a major factor osb $6.00 per sheet plywood 1/2 3-ply $10.00 I'm glad there's a demand for both, it keeps the prices down !!!!