I adopted my dads 28’ trailer after he retired from racing. Sold my 24’ Haulmark. The 28’ is on leaf springs that definitely have required a bit more attention than the torsion flex my old trailer had. There again it went a good 7 years and had multiple trips from SoDak to AZ on it and I used in two of those putting a lot of miles on it too. Shackles and bushings wear out and we had an axle replaced to rid of some weird tire wear issues. I’ve also had a friend that had the rubber on his torsion flex axles wear out and it was a costly procedure to replace them. Disclaimer is that living in the hot/dry desert is hard on rubber anything... most will never have issues. Don’t buy a box trailer with 3500lb axles PERIOD! 5 and 7k axles usually have the EZ lube set up too for the wheel bearings. I do have the 16” wheels and my latest experiment in trailer tire he77 is running G rated 14 ply tires. Longest I’ve ever gotten on a set of trailer tires is 3 years.... again, life in the desert. Not uncommon to pull over and hit the tires with the temp gun and see 160 degrees.