We have a 5K btu hanging out the back of our Eureka TC. This is the second 5K unit on a camper that we've had and both have done the job well with very little noise (62 dbA on low and 66 dbA on high). With some reflectix on the over size windows in the Eureka and reflective paint on the vent covers I manage a 27 degree decrease between outside and inside temps.
We also had a TC with a 5K sleeve unit. The back of the unit was flush with the outside wall. One day after running the unit for about 8 hours on a 96 degree very humid day, I noticed that there wasn't a single drop of condensate water anywhere to be seen inside or outside the camper. I called the manufacturer and asked them where this condensate goes. They replied that I shouldn't worry because there was a tray underneath the unit to collect the water. So I once again asked the same question ... so where does this water go ? They said "it just evaporates". So I asked them "what if it collects more water than it can evaporate". Their reply was that since they couldn't see it, they didn't know :-)