I am a new owner of a 2010 2551S and I must say I am impressed with the workmanship and the coach in general. I have owned several Monaco motor homes in the past and the PC does stack up much better compared to them. With that said, there are several issues that I have fixed on the PC as I am forever attempting to hunt down rattles and squeaks that drive me crazy as well as small engineering issues. Living in a cold climate (NH) I am always looking for those draft sources and did find several....there is no insulation on top of the rfrig.... it is a straight shot from the outside vent to the 1/2" interior panel that is above the refrig. Checked with Norcold and they had no problem as long as there is room for venting and of course there is so I have placed several inches of fiberglass insulation on top of the refrig and the interior noise level in that area has been reduced considerably as well as the draftiness. There is no insulation under the carpet in the cab and there is no way one can put it down since the carpet is glued down...it would have been nice if PC had atleast utilized some 1/8" adhesive foam that would knock some of the cab noise down for sure, I installed such insulation in my Sprinter based coach and the noise level dropped by I will bet 28%. I was able to insulate under the door kick plates with adhesive foam and it does take care of some road noise coming right up thru from the outside. I had many rattles in the kitchen area and discovered that the LP copper lines were rubing together and making alot of noise, I seperated them with make shift rubber bands and bent them some and really silenced everything. The PVC drain pipe from the kitchen sink is all so not strapped down well and vibrates on the wood wall behind the draws and floor as it heads to the back of the coach. I sprayed foam insulation stradegically (completly hidden of course) under and around the pipe and the vibrations are now gone. Had to add the winter antifreeze valve ...do not understand why PC did not install at the factory...all of $14.00 retail. I found the shower enclosure to be somewhat cheap feeling so I sprayed foam insulation from the top and bottom of each of the channels and plugged the bottom holes with nice black pop in plugs that you can not even see....the door now shuts with a great solid feel and many rattles are now gone. I noticed significnat noise around the Kiwee step box....like all of my other motor homes the manafacturer always fails to insulate the cold hard steel that is all there is between you and the outside weather and noise....I again used 1/8 adhesive foam insulation to cover the three sides of the box and that modification really reduces road noise. Will keep you posted of other work I do if it is of any interest to folks? Thanks