I removed my Yucca filata #1 today since it hasn't bloomed since 2006, it gets brown spots on the leaves, and it just isn't that nice of a Yucca. Here is a photo of it back in 2006.
Here's a photo showing the Yucca filata #1 prior to removing it:
The root was so deep and hard to remove I broke a shovel:
I replaced the filata with a Yucca faxoniana/carnerosana:
Here's the dug up Yucca filata #1.........notice the elata type root........vertical roots only.
Here's a close-up photo of the vertical roots of Yucca filata #1: