Flex Drain - personal opinion from an experienced user
The flex Pipe is very light duty compared to other drainage pipe I have used I would not recommend it for shallow underground use because it crushes quite easily when stretched to full length. The one thing I do like about it is that if you use it on the surface to extend gutters for a couple of months it is easy to collapse and store during the summer months. It is also easier to bend around shrubs than standard corrugated pipe. I don't know how long it will last collapsing and stretching out each year because I only purchased it just under 2 years ago.