The forestry cabs that are side entry for both Cat and Deere, that I have done inspections on, were the same size as the excavator cabs. They were EROPS and FOPS cabs for forestry. All that I have inspected had a sloped roofs for debris to fall off of onto the house. The factory install puts the extra cost of the cabs into the base price of the machine. Somewhere I have a photo of a Cat that went several hundred feet cartwheeling down a hill that the operator was able to walk away from once he figured out that the bells he was hearing wasn't a pinball machine in tilt mode. If he had had his seat belt on he probably wouldn't have had to go to the hospital at all to be checked out. If all you saw of the machine when it was hauled to the dealer's lot was the cab, you wouldn't have thought it had been in an accident. The fact that the boom was torn off and the hydraulic tubing was hanging off the front of the machine made me wonder how much blood was in the cab. Turns out none, to everyones relief.