My first condo was very close to the 28% limit on mortgage debt (though I was under the 41% total debt), even though the mortgage was less than 2x my annual income, because (a) interest rates were close to 9%, and (b) condo fees were almost half the mortgage. It was worth it to have a short walk to work. It was tight, but just me, so I still managed to pay off my student loans, start an EF and IRA, etc.

Once we got married, we generally kept our mortgage to below 2x income -- our plan was always to keep fixed expenses to no more than we could pay on a single income, which meant ignoring the mortgage calculators entirely. We blew the 2x rule for a few years when we had just moved and had our first kid and I was working very part-time telecommuting; and then we pushed it again a few years later when we moved back to our MCOL area in the middle of the boom and housing prices were 50% higher than in our prior LCOL area (the mortgage itself was right at about 2x, but the HELOC for the required remodel pushed the total over). But after 13 years of raises + dropping interest rates + paying off HELOC, the outstanding mortgage is about 0.5x gross, and PITI is about 5% of gross -- and that's for a 15-year.

The one thing we have never done is move just to upgrade houses. We have bought and sold homes many times, but always for work moves, and we have always kept to the one-income budget. So we certainly upgraded over time (although, ironically, the townhouse in the DC 'burbs we bought when we first married is probably worth more than my current SFH on 3/4 acre), but always in line with our long-term financial plans. Which did *not* include high debt loads for pretty shiny things.