Though not yet complete, you can see the smooth curves making the figure-8 crossing of the inside mainline, very nice. Trains also move nicely through the "indent" making the cross-overs, with the O72 curves leading in and out of the cross-overs.
There are five sections (highlighted in purble/dark-blue) that need to be trimmed, removing a short piece of the plastic roadbed to mate with the O60 turnouts (without using the 1-3/8" sections in those locations).