I believe bunks do support better then rollers, but that said I have a roller and would never change!!
Here in Mass. most ramps are step and a pain, I have a few buddy's with bunks that have to wait for the tide to launch or retrieve there boats.
They hate it when I can come and go as i please!
I had a single axle as well for the first 4 years and never had any issues.
That is till the tire passed me on the highway! :o
Thats when I bought this in 2005
