They are great looking and should benefit by having the Duramax/Allison combo. The only drawback is that they are considered to be "Class C's" which is a drawback if you get uppity and want to go to a "Motorhome RV Park Only". They usally only let Class A's in. I have read that if you show up with a full sized "front engined" diesel cab Motorhome, you still are considered a Class C, even if it cost a half million $.
From the ones that we have sold I have only heard great things especialy when the duramax / allison pairing. I carry the four winds line and have found there models to be rather nicely put together and it is definately a nicer ride than a regular class c thanks to the added weight.