My vote goes for half doors. The way I see it, with no doors, stuff is going to fall out and if you were to land hard against a rock on the trail, there is nothing there between you and the rock. Tube doors are cool, but pricey. Also, maybe someone who has run tube doors can confirm this for me, but it seems like if you had tube doors they would be 20 times stronger than your cab and sheet metal. So if you put a lot of stress or the weight of your truck up against them, I would think that the pressure would all transfer to the door hinge and cab and cause that to tweak. Perhaps I am wrong, makes sense to me though.
Half doors are cheap (I made mine for $50 and that includes the price of the two doors) and I made mine in about a day. They aren't difficult to make and you get much better visibility, more air flow, yet retain a barrier for anything that might fall out and it still gives you something to rub on the rocks that would transfer stress evenly instead of focusing it all on one point. They also keep out the mud and dirt, which will come right in with tube doors.