I too, had to consider living in a modular unit (from major prodding of the wife), we visited several local dealers carrying different lines of manufacturers, letting her do all the talking since I was not convinced a 'box' was what I wanted to spend the rest of my days in. After serious considerations & actually liking some of the mods that we inspected, I was still not impressed with what goes into such homes. One major problem is OSB used for the floor. It might not be so bad for walls, but plumbing fixtures & pipes will leak. They have exterior glue OSB on the market, but from what I saw, they just didn't seem to use any. Actual plywood is what I want, & I need thickness in a floor, none of that stuff needs to be flexing. The walls need to be 2X6, R19 is supposed to work at that width. The windows, all look to be the cheapest on the market, not that they don't look pretty. Any mod plants use Pella? Anderson? Any house wrap behind that plastic siding? How about wiring for today's modern technology? I guess that's why wireless is available, but my entertainment center needs to have a 5.1 speaker setup. And those electrical panels with the quickie install receptical boxes, just does not seem right, or maybe it was just me. And don't get me started on the kitchen cabinets they use!
Now what did I end up doing. We (I need to keep including the wife) had $5000 invested in a round cement slab that we had built to put a dome home on some years ago & got stopped on it. After smelling something burning from too much thinking over it, I informed the wife that if we did the modular, I was not going to let the slab go to waste, would end up at least building some kind of garage on it after moving into a modular. We also had piles of building materials (doors, windows, shingles, plumbing, electrical, etc.) that was accumalated over the years in anticipation of building something. But right now, I ended up using my mother's log cabin as collateral (which I helped build) to borrow money to build a house on that round slab, but go with a post & beam design instead of the dome that I had in mind since I was an infant (roofing it would be a nightmare).
Alas, it has been a year with all that money bulging out of our pocket (keeping the wife in mind again) & still no house. It's hard to do things on your own. If it would be possible, I'd get a contractor to do a house up to a rough-in or dry-in point, then finish the other items myself such as plumbing, electrical, trimwork, etc.. My main point is, I just want a house the way I want it, the type of materials & workmanship I can trust since I'm able to do some of these functions. I have to live here till somebody runs me over, & hopefully that will be for some time to come. I also have items & designs of the house that will always be a conversation starter at those fancy dinner parties that my wife (er, we) want to have, such as a three-bay commercial stainless-steel kitchen sink, almost big enough for the both of us to take a bath.
So my vote goes:Modular-Quickie move in. You build-the essence of oneself.
J.W.