My personal experience was with a 2005 Monaco Knight 38 triple slide on the Roadmaster Chassis.
We bought second hand in 08. I was very dissapointed with build quality and had many issues with cabinetry and trim work. We only owned it for 2 years and swore to never go down that road again.
This was my 4th motorhome and it was a big dissapointment. I sold a Tioga 31w class C and it was a better product than the Monaco. I had way fewer problems in the 11 years I owned the Tioga as compared to the 2 years I had the Monaco.
It got the same MPG and about the same speed towing uphill. Yes it had more room and drove nicer but not worth the money.
My new MH with the Ford V10 would outrun the Monaco DP hands down. The Monaco was powered by a Cummins ISB at 330 hp.
The Roadmaster Chassis was air suspended and rode OK. NOT fantastic just OK.
I felt the ride was harsh on small jolts. Did not care for the front entry.
The air leveling system was very slow to evacuate and then level, about 5 minutes. It was very nice inside and out just not a positive experience for us.
2013 Winnebago 35G, CHF, UltraTrac 2, 5 Star Tune.
2005 Jeep Rubicon Unlimited Toad