The first difference between models is that some are pole tents and some are frame tents. Pole tents use pole to support the weight of the canopy and keep it up and use guy lines to create tension keeping the tent erect (Think old fashioned circus tent). Frame tents use a frame structure to support the canopy and do not use guy lines. Another difference would be thickness of the vinyl canopy, and whether it is a "black out" top or translucent. Regarding the height, Celina tents are 7' at the sides and 17' in the center. The premier tents also have 17' centers and 7' sides. The Mystique has 21' peaks and 7' sides.