I've been to Mk many, many times & have never seen the concrete cows.
Thing I dislike about the road system in MK is the signage. I know MK reasonably well & can find my way around quite easily, however, I have, on occasion, been foiled by the misdirection of the road signs.
First time I had to take a colleague to MK general I followed the signs which took me on a 12 mile round tour of MK. Whilst waiting at the hospital I asked a member of staff for the nearest petrol station - Asda, 1 mile away.
Whilst there, I bought a road map of Bucks & discovered the road signs had taken me 12 miles out of my way

Another time, coming back from Olney, I followed a signpost & quickly realised the road didn't look familiar, I stopped & checked my map & noted I was being taken on another MK scenic tour

.
Since then I have always checked the road map, although these days I know my way around fairly well.
Have to agree about the speed of traffic around the grid (except for the bit around Ikea, Tesco etc) & with the multiple lane approach/exit at roundabouts there's never a problem getting lumbered behind old codgers. (also find the new L/Buzzard - MK link road 'kin excellent & the A5 is a brill for pedal to metal action.