I would go with the solid axle with the air shocks and the built in air compressor. It will let you change it on the go. The solid axle does not have all the moving parts to worry about. I have had two solid axles and just love them. The most important thing is get a very good installer, even if you have to travel a few hundred miles. I found out this the hard way. Good luck ride them all i feel my solid axle rides just as good as the independant ,maybe a little bit better. My passenger likes the solid better also. Out of all the trikes that i have come across over the years broke down there was a problem with the joints in the a frame usually the rubber boots fail.