About 10-14 months for us. For two major reasons: 1. He had FHO surgeries and couldn't sleep with us for a while (our bed's high up off the ground, too) and 2. I was paranoid when he was smaller - was afraid my BF would roll over and smash P-Nut - this led to many sleepless nights for me when we first tried it, so we kept him in his exercise pen at night till he got bigger.
Once he got bigger and was recovered from surgery, he started sleeping with us every night and he loves it.
We've decided to replace the queen sized bed with a king so there's more room for "all" of us and a potential new pup (someday).