It'll be a lot louder bolted directly to the floor - my old trailer was that way. (That was my point - at least they put SOMETHING under it.
)
There are things that could be better done, but for the price, my Innsbruck SuperLight seems to be on par with others. In comparison with my last trailer ('09 RVision TrailSport - made in '08 before the crash - same price category) there are things that are both better, some worse, and most are about the same.
Things that are better on my Innsbruck:
1. Most floor penetrations had been sealed already with spray foam. There were only a couple that I had to do. (Necessary to prevent mice from getting into the trailer.)
2. The carpet under the water pump, and use of a much quieter pump.
3. Better put together table and counter-top.
4. Much stiffer floor.
5. Roof vents and other penetrations had been taped under the flanges, and then sealed with Dicor over the flanges. (My old trailer just had the Dicor over the flanges, and had to be re-sealed after a couple years.)
Things that are not as good:
1. The roof is definitely not walkable without being really careful to keep my feet on the rafters. This also made doing the solar installation harder. I'm a lightweight guy - 160 lbs - so this was a surprise. I hope it holds up well to snow loads.
2. The outside seams (corners, around windows, and the like) had some gaps in the sealant. I went around the trailer and carefully sealed over all of them to make sure I don't get water in. (To be fair, the wavy aluminum is much harder to seal nicely than the smooth walls of my old trailer.)
3. The through-the-wall AC wasn't draining properly to the outside of the trailer. (The water was running down the inside wall to the window under it, then coming out the weep hole on the window frame. Yikes!) I pulled it out to re-work it and also discovered that the sheet of aluminum that they had it sitting in was blocking both the right and left side vents on it, so re-worked that too. I left it blocking the left-side (so that it wouldn't pull air from inside the trailer through the power cord hole) but cut the right side down some so that the vents could get air from outside (which comes through a refrigerator vent mounted through the roof - while it was out I ran the solar wiring through this opening too). I very carefully (to keep from puncturing a coolant line) drilled a hole in the bottom of the lowest part of the drip pan, where it sits in the outside trim on the trailer, so that it now drains outside, and put some plastic sheeting over the wall, screwed down so it stays put, so that any water that misses that hole gets directed outside too, and cut a hole in the outside trim for this water to drain through. It seems to have worked. It should also function better (although it did work fine already).
4. The cushions on the bunk beds are REALLY thin. I'll be putting additional pads under them.
5. No winterization bypass for the water tank had been installed (but there was a water-heater bypass installed - go figure).
Most things are the same though - such as the quality and construction of the cabinets, cloth on the cushions, dinette cushions, flooring, interior walls (thin), lights, wiring, etc...
Both trailers came with minor plumbing leaks (fixtures not screwed on as tightly as they should be), so don't feel too bad about that one.
BTW - there are trailers that don't have issues like these (Northwoods Mfg comes to mind), but they cost more.