No it isn't. The debt, as a percentage of gdp is the CORRECT way to measure it.
After thinking long and hard I've come to the conclusion that you are unfortunately wrong. The debt as a percentage of the GDP has swung up and down, at times dramatically, all while the hard debt has perpetually increased. It seems to me that debt as a percentage of the GDP is a consequence of multiple factors (most directly the strength of the growth of the economy), and as such is not a "correct" way to measure debt increases. That is not to say that it's not an important factor to be aware of. It seems that the growth of the hard debt, as well as the percentage of the GDP as a measure of debt are both
indicators of the health of the economy, though neither is all telling.
Let's put it this way.
If you owe 10,000 but earn 5,000 a year are you in good shape or bad? Obviously bad.
If you owe 1M but earn 1M/year are you in good shape or bad?
If you owe 10k but own stuff worth 5k are you in good shape or bad?
If you owe 1M but own stuff worth 10M are you in good shape or bad?
Yes, debt as a percentage of GDP is a valuable measure, probably the only valid one.