Ozzie does both, too. Almost always will go once outside but that's never his primary objective. More interested in playing with and smelling everything.
Had some BAD marking experiences the first year or two and but he got fairly consistent about peeing on the papers. When we took them up, he peed where they used to be ... so we returned them. Have never been able to successfully turn him to outside only and finally just caved.
Every once in a while he will mark if he's mad about something. And sometimes, you have to remind him to "go in on your potty" and he will. At night, if he sleeps with one of us, he will kiss you if he needs to go. Doesn't happen often though. We just set him down and he goes in on his papers.
We're just thankful he uses the papers now. It works for him and for us, so why make each other miserable over it?