Something that hasn't been mentioned here is the weak points of stock Nissan IFS and the benefits of changing to a solid axle.
IFS is strong enough to stay together in stock form. The steering is another story, but still.
Modify the IFS with a lift kit and take it offroad anyplace other than a mud puddle and it will start to degrade/wear out all the bushings, the CV axles will wreck themselves in certain situations, and the steering parts will certainly be ruined in short order. Many other parts will fail(balljoints come to mind), especially if you run bigger tires.
A solid axle in stock form generally has none of those weak points to contend with in the same offroading situation. Even with bigger tires. It is a stronger setup to begin with and can handle the stresses much better with fewer moving/pivoting/bushed parts. That's why it is considered to be an upgrade and people are impressed with it so much.