Daniel,
There are several great points being made here. I can tell you the Cyclo can correct some fairly moderate damage.especially with the MF pads. Like Darrell, I have experience with several of the Adams polishers. If you are looking for just one polisher, I would lean towards the Cyclo. It is very versatile and very high quality as well. You said your truck has rough patches. Do you have pictures or can you go into more detail?
The Flex is a heck of a machine and I would agree you could get it and a Mini and pretty much be covered on most vehicles and situations. But if you just get one, I would lean towards the Cyclo with the Rupes 15 a close second. And yes I would wait for the new version of the 15 if you go that way. I know it seems like I am putting the Flex down. I am not, I am just thinking of your experience and what you are using it for along with the fact it seems you want just one. Technically, I think each polisher has a place if you do enough detailing. If you were doing a lot of cars and speed was the ultimate goal along with being able to correct hammered paint frequently, the Flex would be it.