i can't advise you on schult but i thought these websites would be helpful in answering your second question?
i used to consult to epa/doe. i learned a lot about energy efficiency. it is a great way to "grade" or evaluate how well a home is built. the more energy efficient, generally the better built (and more expensive!!).
i looked up a lot of floor plans on net and got them from dealers. i cut and pasted to make a floor plan i really liked. then, i contacted the "dream home" manufacturer for my state. it's called colorado dream homes. this line of partial stick built/partial manufactured home has an exceptional energy rating of 87 (it goes up to 100). they average $75/sqft. they have 12" thick walls, r38 throughout (not just roof), vinyl siding guananteed for a lifetime (!) and a propanel roof that the industry has proven is extremely low maintenance and is also guaranteed a lifetime. i think many states have dream home contractors. try bbb of your area or do a search with your state in front of 'dreamhome.com'. the reason they are not building for me is this builder requires 1,500sqft minimum. that's too much home for me.
i am trying an experiment.i looked up a lot of floor plans on net and got them from dealers. i cut and pasted to make a floor plan i really liked. then, i take the specs of the dream home and ask the dealer how close they can come to the specs and floor plan and how much it will cost. in this way, i am comparing all dealers/brands to the same standard.
mr. murray said to go 250mi to all dealers available.
if you'd like to get an update on my progress, you can email me and remind me.