looking for a 5 ton zero swing mini 10 thru 12 model around the 2000 hr mark, which unit would best hold up to normal use, and not be a bag of bolts after some hours of use??
Any of the major brands are worthy machines ( ducking before the brand wars start) . It is far more important how the machine was treated during its adolescent years. Rental machines are generally operated Poorly by inexperienced operators which ends up causing all kinds of hidden issues with them. For instance a local guy I know with a pretty good size rental fleet just got one of his skid steers back with fuel in the hydraulic tank because the "operator" didn't know the difference of the fill locations. Maintenance and reasonable operating conditions are the key to long life for equipment. Even the cleanest scratch free machine can have hidden issues it's always best to have/hire an experienced mechanic to look over a used machine if possible and ask the right questions about why they r selling it. A lot can be learned by talking to the owner of the machine prior to buying. Another important consideration is dealer location for parts support. If you live 10 minutes from John Deere and Cat is 2 hours away that should figure in too
I think if you go mainstream north american they're all pretty good from that era. JD, case, bobcat, yanmar, blah blah blah...
Just don't blow your complete budget and save $3-4 aside in case you need a decent repair