DD1 slept in the pack n play all of the time from birth to 6 weeks old. She started sleeping in her crib during the day at 6 weeks old. At night she slept in the pack n play until she was 3 mos. old., and then moved to her crib full time. She stayed in her crib until she was 2 yrs. 3 mos. old.
DD2 didn't like the Pack N Play when we first brought her home so she slept in the Uppa Baby Vista bassinet until she was 7 weeks old. She took to her crib for both naps and night time pretty early and has been in there ever since.
ETA: DD2 also loved sleeping in her Nap Nanny!