We used to buy Precision 5500 series laptops (latest model: 5560), but they have issues with thermal management. Over time, the battery expands due to temperature to the point of moving the trackpad up. Now we are giving Dell a new chance using the 7500 series (now 7760).
The 5560 is between 7.7mm (0.30") (front) and 11.64mm (0.56") (rear) thick. The thickness of the 7560 is between 25 mm (0.98") and 27.36 mm (1.08"). The increased thickness should solve (or help solve) the overheating.