I also have set up many real moduler homes, so as long ago as 25 years ago in NH . And I 100% agree with the poster that the quailty varies all over the place on these.
It's a shame companys like Clayton, Champion, Fleetwood were allowed to try and pass there mobil homes off as Moduler. It distroyed the market with there cheaply built homes. A friend of mine does the punch list for Fleetwood in this area and everytime I see him he has at least 3 pages of flaws he has to go back and fix.
People and bankers in some area are under the mistaken impression that modeler are something new and there all made like trailers so have less resale value, so it's harder sometimes to get a loan for one or even be allowed to put one in certin area because the locals think it's going to bring down there property values, even though it's not true.
I've also seen time and time again where the hacks that the company sends out to finish off the home just do not care and mess up a perfectly good home.
Things like when there installing the siding on a very cold day cutting it to tight so the first warm day it buckles up. I caught them installing seamless gutters with sheetrock screws because they forgot the box of hidden hangers and put a seam right over the front door which of cource leaked.
There was a dead circut to the master bathroom so they ran a while new line, which is fine except they ran it right over the water filters under the house so tight that we could not change the filters.
I found where someone had broken off the whole top, back side of the nailing flange on a big window and all they did was dump two tubes of caulking in the hole instead of replacing the whole window.
Most use preformed vinyl fashia material, it never works and just buckes up and falls off.
Time and time again after screwing up all that stuff the home owner would give them the job of adding a porch or a garage onto the house instead of paying my company.
They added a one car garage with no flashing between the two building, The shorted the sheathing for the siding on a block knee wall so much you could see cars drive by. Installed shutter of a differant color then the house.
Installed the ledger board for the deck by just nailing it to the vinly siding and while doing that punched a hole in the siding.
It got so bad people were hiring me to stand around all day and make sure things got done right.