As you can see jbatz, there is no right answer. You must calculate intangibles such as "living in a new place with new appliances", making the wife happy, knowing you won't be forced to move from a rental if the owner sells, knowing you have cost certainty for x years. Then you also have to make sure you can ride it out if things do get bad, one of you loses a job, etc. Think about the worse case scenario and ask yourself if you would still be ok with your decision to buy.
I've been living in my Lennar home for a month now, and I love it. After renting for years, I get so much value from having my own garage, decorating the place the way I want, not sharing walls, peace and quiet, the extra room, etc etc. Some people don't value these things as much as I do, and won't be willing to pay a premium. Ask yourself how much you will value owning a new home vs renting.
Another thing, not everything was fixed after close of escrow, but you have 30 days to request fixes. I'm going have my 30 fix tomorrow to go over little things. Overall, I've been very satisfied with the level of service. I was wary of build quality as well, but I have no complaints so far.