This picture here shows only the tractor portion but it shows how small the space is between the firewall where the shift lever is and the steering wheel and seat.
It would appear that you would have to have the dexterity of an octopus
to be able to slide your legs downwards into the driving position.
It could be done, you would just have to sort of slide your way down and in. If you have a tall cockpit, and you enter the area in a standing position, getting into the drivers seat would be easier than a low roof where you would have to crawl or slide your way in.
Muddy boots would make a mess...
I guess you could always use the drivers door and then enter the side door of the cabin.
Keep in mind, if the steering wheel is tilted all the way back, you could pick up a few inches of space when you push it forward...or if the front seat is pushed back...
I still like the idea of the cabover though. Seeems to create more space in the cabin.
Anyone want to comment? Free, no charge.