I'll agree w/what others have said, I have several wheelbarrows, some w/solid tires, some w/pneumatics. The rolling resistance is > on the solid tire. They handle a bit-differently, to me it feels-like the the solid tire squirms when the wheelbarrow is heavily-loaded, and you try to turn, or you lean the wheelbarrow, which is pretty-much the same-thing. I like the no-maintenance aspect of solid tires.
Encountering height obstacles, the pneumatic tire does for me make it easier to cross the height difference.
I've had my first solid tire for maybe 6 years now, it still works fine, and I see no sign of structural failure.
I have a two-wheel wheelbarrow, which you have to learn how-to drive, but it's more-stable to me, I find it a bit awkward because a tricycle wheelbarrow is easier for me to operate and maneuver, but not as-stable as 4 wheels.