Funny Burl, it was a BT that showed us the light. We were at the Pennsylvania RV Show and my wife and her friend went into one before me and said:"why can't we get one of these?". I was dumbfounded because I didn't think she would consider anything bigger than a B. Your further description above was also right on the mark, since I knew about Coach House and Chinook. When they heard the price, "why do I want something that seems smaller for twice the price??"
Both sofas 'sit' nice, especially the drivers side since that uses the old dinette backs. DW and I found 2-24" square pillows in Bed and Bath that will provide the 'leanbacks' for us to watch the tv. Since the tv is in the front, we don't forsee changing the cab seats to swivel. Nice idea tho', great for a slightly larger rig!