Hello everyone, just discovered this post and read it all. Wish all the pics had been available when I bought ours a couple of years ago (april 2015). A couple quick responses to issues mentioned in thread: 1 black tank runs from front edge of slide to 1/3 of length of couch under sink, toilet and front of couch. Bottom floor of sink cabinet lifts out (at least in mine) so you can see front edge and water lines running to sink.
2. Mattress options; We have a queen size sleep number bed in ours(camping world). Moved over from our previous TC (alpenlite 1100). Much easier to move than fighting with original foam mattress options we use to have. Would want to do it on a regular basis but not terrible. Put compressor in bottom of driver side closet and put small hole in closet to route air hose and power cord to front of mattress. We find it comfortable.