I did a modular about fifteen years ago and have no complaints about the construction. They are "overbuilt" compared to a stick build because they have to be transported to the site. Look at the sections when the pieces go together, you get twice as much wood. I deleted the kitchen, all the woodwork and some of the carpet. Went out and picked my own products to finish and had my contractor install the kitchen, trim and some flooring.
You avoid your house being exposed to the elements when it is being stick built. It also saves a lot on building time. You just have to do some homework on what "modular" company you want to go with. There are a lot of them out there!