I read Lyle's body composition measurement articles from his site. He does go into extensive detail about the differences in terms of relative ease, reliability and cost, but, I don't remember reading anything about DEXA producing results substantially different than calipers or BIA in either of those articles.
The linear software site you linked looks promising. I'll have to practice taking measurements or teach my wife to do it.
Also, Craig, thanks for the lacto-paleo idea. I've never heard of it. Something else to read up on. Truth be told, the high fat DEXA scan scared me a little. It's really unhealthy. I thought about putting on some muscle first and then leveraging the extra calories that muscle would burn to get lean, but, I finally decided I need to lose some fat first to get down to a more heart-healthy level. Again, I'm not sure if I need to make some adjustment between my DEXA scan results and the numbers posted on the linear software site, but, my 27% DEXA result puts me in the obese category. Gaining muscle will almost inevitably lead to even more fat.
I'll probably try to drop 15 pounds or so of fat, then gain 5-10 pounds of muscle, then drop another few pounds of fat, then gain the rest of the muscle.