The main difference between the QSH and my QDH is the toliet room/shower/2nd sink arraingment. The question should be about the overall quality of the '06 Phaeton. I have had to have the wet bay floor replaced (warranty), I have not had any of the troubles with roof side rails that the later models with changed design and darker paint have experienced. Do try to select one that has the HWH jacks and stay away from the Atwood Level Legs. At that age check the date codes on the tires, exam or have examined the slide seals, I've just had to replace both of the rear ones. Check the shear bolts on the front driver's side slide out. Make sure the tubing holes are not wallowed out (easy fix) and/or the bolts are not broken, bent or otherwise damaged. Check for complete maintenance records. The CAT C7 and Allison 3000 have performed flawlessly. My bays have never leaked. No leaks of any kind except after to high wind downpours that indicated the rear slide seals needed replacing. Dried the carpet, replaced the seals, all OK. I generally get in the high 7mph pulling almost 3 tons of GMC while running around 60 mph. I bought my unit new in June of '06 and as of right now, unless I win the lotto and can buy a Newell, have no plans to replace it.
Travel well, travel safe,
2006 Tiffin Phaeton - 2011 Cadillac SRX