I bought the Vortex Freedom a while back, and while it works well, it is an incredible PITA to set up without making a huge mess. The priming process is very annoying, the built-in diversion valve is not good (it leaks both water out of the system and air into the system unless everything is "just right"). The hoses are horrible, and collapse/twist up all the time.
Other than that, it's great.
Meanwhile, the UV
I bought installed inline to my cannister filter, and has required 0 effort or maintenance since that day. Someday I'll have to clean the quartz tube and change the bulb, but otherwise it just works.