Driving an arctic at 56mph come up behind a slower truck, look in mirror and road behind clear, by the time you've pulled out there's a BM or Merc behind flashing and hooting....

Sounds about right. Also part of the reason why so much road in Germany is single file only for HGVs, they can only go as fast as the slowest truck. Must drive 'em nuts. 
Something I think should be used over here between certain hours on major routes (like the A14 etc).....the same as on four lane plus sections where lorries should only be able to use the first two
Agreed. Any lanes HGVs are allowed to use will be fully occupied by them, due to their love of 5 mile overtakes with a sub-MPH speed difference.

My experience of derestricted autobahns has mainly been on 2 lane roads where HGVs have monopolised the inside lane, leaving the outside lane for all vehicles travelling between 60 and 160+ MPH.

On one occasion, I was in a hired Twingo which would do about 90 MPH wringing its' neck. I quickly discovered that pootling along with the lorries was the key to self-preservation in that POS!
The other time, in the Omega, you had to be pretty aware of what was going on ahead and behind. As a car pulled out from between lorries when stretching your legs you ended up closing on it pretty fast, and normally with a Merc right up your @rse too.

Sadly I haven't experienced autobahns with little to no traffic, where I'm sure they are fun but with any normal level of traffic I find our motorways a
much less stressful place to be!