Hitler's Germany was in no way technologically inferior to the allies. Its really about money.
Actually, it
was, but it had waay more to do with several decades of global economics than it did with form of government. Its just that in looking at the period of WWII, war buffs tend to focus on a few specific outstanding military devices, and overlook all the liberal democracies advantages in basic processes, production technology, martime technology, electronics, metallurgy, automotive mechanics & reliability, etc, etc.
On the subject of technological potential, you also have to note the brain drain of innovative (but generally Jewish and/or liberal) thinkers who deliberately left the Nazi sphere.
The Nazi's probably did improve the situation (economically and technologically) in the early days, mainly by stabilizing the financial system, improving the investment environment, and massive government contracts (whose bills wouldn't come due until they had some [ahem] 'outside' sources of income).
Later on, the Nazi leadership's micromanagement of research resources into bizarre sidelines often stole from general technological progress, despite Speer's best efforts otherwise.
Does this translate to a general lesson about 'evil' regeimes and technological progress. I don't know. A lot depends on how you define 'evil' I suspect. But certainly cultural systems that place artificial limits on what is 'acceptable' technology and research, and who are 'acceptable' thinkers, are limiting their potential progress relative to those cultures that are open to more sources of innovation.
drrider