The reason the high-end ones are heavy is that everything in them is heavier, and that's why there's so little issues with them full-timing in one place or moving all the time. Look at the so-called 'ultra-light' trailers and they're made almost out of cardboard, with tiny tanks as well. Our Montana was a compromise for us, although my wife did get the floor plan she wanted most. It was the heaviest I wanted to tow even though it's also is the heaviest my '06 F350 is rated for. Just finished over 5,400 miles towing it over a 9 week vacation and nothing broke on the 5er (a couple of glasses did in a cabinet though) or the truck.
If you want something to full-time in, you should figure out what your needs and your requirements are (each is probably a little different) and go shopping with a good checklist in hand. And, you can usually get a good three year old unit for around $40k if you look hard enough.
2010 Montana 3665RE, wet bolts, etc.
2006 Ford F350 Diesel Dually, air bags, Softopper, Aeroshild, etc.