Atlas has just released their new Z-scale flextrack and I just got my first box with 25 pieces i house. Its looking great, prototypical US spacing, similar to the Micro Trains flex track. Easy to bend in fine curved shape and the length is good, 24 inch.(610 mm). Holes for the Nails are missing, so then I must use glue to fasten the track. I prefer nails, bit it will work.
Märklin flextrack at front, new Atlas Flextrack in the middle and the MTL track installed on my layout. The Märklin track has not the prototypical spacing for US layouts, compared to the other two.
With a complete box of 25 pieces, I have plenty of track for new projects. 25 * 610 mm: 15.250 mm, more than 15 meter of tracks. Nice.