looking good. I too, took the 5/8 OSB route for my sub road bed. After four hours working with that equals about 30 minutes of splinter pulling. All in all, I do like the fact that its not as "directional" as Plywood, which has led to verry little waste. I was going to paint it, but instead, I am going to skin it over with ceiling tiles turned up side down (Can't get homosote or quiet brace here) then run a base coat of paint over that.
Keep up the good work....
Ryan