In my opinion, an hour per pound or more is way too long. 12 or so pounds is as large a turkey as you should try on a smoker, otherwise internal temperatures of the bird stay in the danger zone too long. One 12 pound turkey should take about 6 hours (if you do two at a time it will be another couple of hours) at 250F, about 30 minutes per pound. Outside temperature and wind may affect cooking times. I did 2 13 pound turkeys last thanksgiving and it took 8 or 9 hours. That's a lot of cold meat to put on at one time.
I have never had a 10 to 12 pound turkey take more than 6 hours on the grill and they have all been up to temp, juicy and tasted great. Too low and too slow with turkey will dry out the bird. I also quarter an apple or two and put it inside the bird to help keep it moist. Don't know if it actually helps or not, but I have never had a dry turkey.