I find when driving on German autobahns i'm more alert and focused on what's going on.
100 or 'it won't go any quicker' ... constantly aware something's travelling faster than you ...
As a result, lane discipline seems far better,
you HAVE to get outta the way in plenty of time or be tailgated and flashed by huge mercs and audis B)
On the other hand, i have 2 relatives who both got done speeding in Germany...
and both at speeds below 20mph.
It seems where there's a need for limits, they're there ...
built up areas, before + after autobahn on/off ramps and bad weather for example ...
And where there's no need, progress as you please ...
Concentrating on driving rather than looking for sneaky cops and cameras.
All seems perfectly sensible to me.
Then cross to UK with arbitrary speed limit figure from the 60's plucked out of the air ...
Progress is drone like and artificially restrained = lack of concentration = problems.
Ever notice traffic moving freely ... ooh look, police car doing 60 on inside lane, traffic instantly jammed up ....
So, i vote German... Sensible limits where required ... Unrestricted where they're not.
But then i usually do go for the common sense option