Exactly why we don't use casters with wheel locks, not because we don't want to, but because I have not found any that were any good. At least not with out adding $400 to the cost of the unit, I keep thinking I will eventually find a good caster with locks but it hasn't happened yet. On another note I cooked whole chickens on my insulated at the house on Sunday. When I dropped my lite coals in the fire box and shut the door it was 1:50 pm and the guru was reading 50 degrees. My desired temp was 275 degrees and I had no water in the pan. At 2:13 it was 250 degrees and at 2:25 it was 277 degrees. It will actually get there quicker but the Guru knows to slow down the fan as it approaches your set point so it wont over shoot. Near the end I went to 300 degrees for a couple minutes just to crisp up the skin and it took less than 10 mins to make the jump (output on the fan wasn't very much here either or it could move even faster).