Here's my .02, for what it's worth...I haven't actually used a UPH myself, but have considered it in the past. With the FTP it seems to be a good deal. You didn't mention the ages in your group, but in my opinion the pass is best utilized if you hit the parks every day, and if you need a break, then at least a few hours one day in a water park. On the evenings you don't choose to stay late in a park, you could do Disney Quest or Pleasure Island. The beauty of the UPH is the unlimited admission to DQ and PI, in my opinion, and the freedom to hop between Blizzard Beach and Typhoon Lagoon without using 2 plus features in one day, if you so choose.
The UPH gives you lots of freedom to come and go as you please, without considering admission prices...however, there's also that pressure to not "waste a day" that is paid for should you prefer to have a non-park day. If you wanted to go to other Orlando attractions, I would plan to do it before or after your FTP is in effect.