Wow, big difference at 50 ft! Here is a link to a video of a ham operator that is using one of the HDBX towers. As you can see they are quite substantial. Takes quite a chunk of concrete to support one.
https://www.youtube.com/watch?v=fD0ca90nKC4 The trade off is $$$...it will cost a bit to get to that height if you must use a tower.