Welcome to the forum.
It has either a Ford V10 or Workhorse chassis/ Chevy 8.1L . Itís not a diesel. Mine is the Chevy & itís so quiet that many have seemed surprised that itís a gasser while ideling in the campground. Contrary to the popular conception, DW & I can talk comfortably in the cockpit while underway without any problems whatsoever. Mountain-steep grades warrant lower gearing and the accompanying engine noise; but we have no complaints on pulling power nor sound as it is engine/tranny sized to suit. Toad hitch is 5K rating & we tow 4K automobile with no issues whatsoever. Never know itís there.
We fell in love with the floor plan and the specious wardrobe spanning across the rear cap. Other models suffer from smaller size wardrobes. Interior storage is the best Iíve seen in a 34 footer. We have a Splindide combo-washer-dryer. Great appliance. Lavatory counterspace is one of the more generous layouts, we have plenty of storage in there. Woodwork and trim is top-notch, the carpet/tile so-so and the wallpaper/ window valences very appealing. Lighting fixtures & Plumbing brasswork are very good quality and hold up very well. Appliances and rooftop units are hearty and great performers as well. Not a problem with any of ours. Insulated double-pane glass windows are a must-have for us both for the sound-proofing; but more important: thermal insulation it affords. Basement storage is quite generous considering the limitations of the gasser chassis; but I find it all suitable. We can seat four comfortably with the two slideouts being just right for our needs without missing-out with the 4-slide. Overall, we are well pleased with this floorplan selection. FWIW: two friends full-time in their 34XB & frequent the Rockies and northwest US.
My í04 had the Bosch brake recall done, the Dometic fridge heat guard installed, and the Actia instrument panel Pixel-drop display problems. Check for these campaignís resolvement if they apply to your year model. [Brake work would have a yellow paper decal next to the master cylinder. Fridge will have a sheetmetal guard surrounding the outside burner. Instrument cluster LCD Display will be clearly legible without any horizontal lines ,or. noticeable image loss.] Again, these apply to my year & might not to the í06 model; but, you will appear to be knowledgeable in this regard. Check the date on tires and use that upgrade if needed as a bargaining point. Patio canopy might have some wear; but itís a minor item. See if vehicle maintenance log done and check the entertainment wiring for upgrades for DVD or HD TV. Most owners cannot resist the temptation to customize.