The official test reports from the Korea Testing & Research Institute, a State Institute, performed for the approval for Korea Industrial Standard backs up the benefits of COD as follows:

Item
Specification/Performance
  a. Material
Polyethylene (HDPE)
  b. Length
No limit, but 500m to 1,000m for practical use.
Customer's order-length is acceptable.
  c. Flexibility
Free bending up to any degree by man-force.
(Provide much better resistance & stability against earthquake compare to the conventional duct owing to sufficient flexibility
and elongation nature).
  d. Compressive Load
< 292Kgf/CM2
  e. Heat Resistance
-0.4% (at <110กษ)
  g. Thermal Deformation Factor
<3%
  h. Tensile Strength
321Kgf/CM2 (at 5% deformation of outside diameter).
  i. Friction Factor
<3%
  j. Heat Transforming Factor
<3% at being stored 60 minutes at 110กษ
  k. Impact Test
Passed (Free from distortion, twist and tear.)
  l. Bending Performance
Bendable up to -20กษ temperature
  m. Chemical Resistance        (Appearance)
Test from Solution form of the following Chemicals
No defects at: 40% of HNO3
No defects at: 40% of NaOH
No defects at: 30% of H2SO4
No defects at: 10% of NaCl
  n. Voltage Resistance:
AC 2,000V (< 15 minutes)
  o. Insulating Resistance:
< 200M Ohm