Although many carry items up front, I feel the air restriction created is not acceptable for summer use. Many people argue that snow plows are mounted on the front, but I don't see many driving in 90-100 degree weather. I do have front axle and suspension capacity for a heavier bumper and winch, but other priorities have put this lower on my list.
It is true I do not have to worry as much about rear axle capacity on my Class 5 truck, but that was just one of the reasons I chose it over a Class 3. I didn't weigh my 225/70R19.5 tire on a steel rim, but my 245/70R19.5 on alloy was 125 lbs. My spare sits about 3' farther back than if it was installed right behind the rear axle. This is not possible on a chassis cab since the main fuel tank occupies this location.