I used the ETD Quadra Step based on Mikey's recommendation and we are very
happy with them after 6 months of everyday use. I did make a step support to get rid of the sponginess. It clips on the
2nd step support bar as it must be removed for folding.
The Smart Step is an aluminum ladder contraption that fits over the OEM fold outs. It has a rail that attaches separately.
The website was
www.rvsmartsteps.com not rvsmartstep.com but is defunct.