[atreis]

x2 - In either case if you have a flat, you have to stop and change it. With the tandem axle trailer, the additional axle is there to allow for more weight capacity, not as back-up. After you have a flat, the remaining good tire will be severely overloaded. Also, the tandem axle's load adjuster will push the flat tire down to the road - if you keep going it will shred and could do quite a lot of damage to the wheel well.

I've had both tandem and single axle trailers, and there's very little real difference. My tandem axle trailer absorbed potholes better (makes sense too). The single axle trailers are less expensive on tolls. Neither is a big deal.