I'm am very happy with the ease of converting these to 2 rail. I've converted two of these cars both in the GNTX/TTX paint scheme.
The only problem I have is, Lionel did not separately apply the underside details. Also I suspect the coupler height may be too low. I will order at least one more. These 66' gondolas are the only "modern" 21st century gondolas in O scale. Atlas seems to refuse to make their Thrall/Trinity HO gondolas as part of the O scale lineup.