I love my X. I chose it over the yuba because the X seemed to be more versatile. I have no experience with the Radish, I would expect that it would be a very solid (as in good) ride. It probably would have been cheaper for me to have gotten a radish. However, I have no regrets, It has been a learning experience all the way for me.I hadn't been any where near a bike in over 25 yrs. I didn't know enough to know that I should have gotten a steel framed donor bike.If I was going to do it over I would probably get the Radish,assuming that the budget wouldn't allow a Big Dummy build.
Having said that,if I had the resources I would have a Big Dummy in a heartbeat.
Either way I believe that you would be happy which ever way you decide to go.
As an aside, if the budget would/will allow it consider an e-assist option.
Peace and Blessings,
John