Agreed regarding speed limit, though i've no problem with 20/30 in the right place.. residential areas, near schools etc.
Primarily my problem is with Motorway limits though. I think we've all on this forum done over 70 before and can appreciate how much it would suck to be 'caught' by intermittent and inconsistent policing of speed limits. Clearly 70mph is too low as the police are perfectly happy if you're doing 80 and most people do.. it's commonplace, but the ACTUAL speed limit is now set at 100mph because policing policy enforces 100mph+ with a ban/court etc.
The lesson to be learned is that 100mph+ is now NOT ok, and there are consequences, whether it's safe to be doing that speed or not (I guess you could be thankful there's actually now some consistency in the policing of this particular limit, whether it be right or wrong - and not so nice for OP).