Hey Jay,
My outside runs are only covered by Sunscreen (black Fabric) in the summer. ; so they are very exposed to the weather. I am sure they can make it another 2-3 years without too much problem,but I'm boarding clients dogs and have to consider appearance,safety,etc. ... Some welds have broken where the wire meets the frame, but overall that is no big deal. The frames are rusting badly where they meet the ground and I actually cut 1" off the bottom to remedy this. Also the powder coating has peeled off here and there and is starting to rust. I look at all this as normal wear and tear. My indoor runs are in Very Good condition still. Hope that helps.