One really good source on who builds the best homes are the cabinet guys who install them. Trim guys are another good source. The reason these guys are so good is they have to deal with fitting there materials on home that are not square, the walls are not straight and basically, the framing is sloppy. Mirror guys have also told me some horror stories of trying to get there mirrors to hang on walls that were so bowed that they have to remove the sheetrock, or add lumber to the wall to get a flat surface.
There are two types of home builders, those that hire crews to do all the work, and those who do it themselves. I've found that the builders who do the actual building, do the best jobs. Just like Harvey said, when you hire the cheapest people to build something, you get what you pay for.
I have a client who hires crews to build his homes, and from time to time, they will mess up so bad that he calls me in to fix them. I've torn down entire sections of walls and started from scratch to get the windows, doors and walls where the plans say they are supposed to be. I've taken out studs that were too warped to save and just stupid to have put in. Headers that were too small, corners that were not square and lots of walls that were not plumb. The list goes on and on, but the point is that these were all high dollar homes being built by a big local builder that usually puts out some nice homes, but since he's always using different crews, it's just a matter of time until he gets a bad one.
Just to add to that, sometimes it's also the son of the owner of the company that doesn't have a clue, but since his dad owns the company, he runs the show. This only happened once, but the kid was just clueless. He drove the big, brand new truck, spent all day on the phone and considers himself to be quite the big shot. After he was done frameing up the house, his dad came by to take a look. It was a disaster. He called me over and had me fix or redo allot of that house. His kid never showed up while I was working on the house and I have no idea what was said between them, but he paid me cash when I was done and I've never heard from him again.
Eddie