Hi Fred....and welcome!
We have had our 2552 with laminate floors and a 15000 BTU A/C for a few years now.
We have cherry interior and the darker, matching laminate flooring. We bring our two Pomeranians with us on most trips and have camped in cold, hot, wet, snowy, sandy, muddy conditions. The floors still look brand new, have performed extremely well and are easy to clean. Even in the bathroom area which tends to get a bit more water splashed or dripped around. Due to their dark color, however, they do show dust/dirt more readily, but we think this is a good thing (ensures we clean regularly)
We found that the originally mattresses were marginally ok for us and opted to just purchase our own foam toppers.
Personally, I think the 15000 BTU unit is necessary for us. We do camp in some of the hotter areas (Nevada, Southern CA, Arizona, New Mexico, Florida, etc) and enjoy getting out of the heat once in a while in our rig. Even with the additional BTUs over the stock unit it can only cool down the rig to about 20 degrees below the outdoor temp. So, if it's around 100 degrees outside the best we can do inside is a bit below 80 (with shades drawn, windshield covered, heat source like tv on, 2 adults, two dogs, etc.) Obviously a 13500BTU unit wouldn't be able to that well. We have found that there are many folks who don't run their A/C unit at all in that type of heat...personal preferences. The units will draw different amounts of power, so if using a 15000 BTU unit you will be more limited as to what else you can run at the same time. We upgraded to a 50 amp electrical system in our rig due to this. We can easily run the a/c and other things like the microwave at the same time. From what I can tell, the Coleman Mach8 unit that we have may actually run less noisy than the stock 13500 units, especially on low fan speed.
The heat pump vs regular A/C issue is a bit more complicated I think. Overall, we thought there may be more issues with a heat pump. In more temperate climates you'll get better heating in a heat pump system vs the electrical heat strips and won't use up propane by running the furnace. On the other hand, there would be more noise running the heat in a heat pump unit vs the heat strips as the compressor will be running. The propane furnace is also much noisier than running the A/C heat strips. Running the heat strips doesn't blast out the heat as one might expect. It does heat up the rig, but actually might feel a bit like coolish air if you put your hand up to the grill. Lastly, generally somewhere between 30 and 40 degrees the heat pump won't operate in heat mode due to its inability to draw heat from the surrounding outside air.
We are generally happy with our choice, but because of personal preference and the experiences we've had we might have liked the two HVAC unit option a bit better. That would allow use of either or both units which would have increased overall heating/cooling capacity and allowed better noise control. Of course, the 50 amp electrical system would also be needed here.
Hope this helps a bit.
- Mike