The first thing to note about RRW 23 was the timing - the previous weekend had seen temperatures of 30c across Britain. The weekend we went to Wales it tipped with rain - not constantly, but quite a lot. Also it was the weekend when "all of Wales" went onto 20mph speed limits. The implementation of this was chaotic at best.
As I understand it, the word from the Welsh gov't was "put a 20 in the towns unless it's a major road with lots of traffic" - which undermines the "safety" argument - isn't that exactly where you would want the 20?
In the middle slice of Wales this seemed to have been done with a descent dollop of good sense, 30 limits on the approach, 20 limits in the built up areas where the pedestrians were, but in the north, there were times when we were driving in between fields for miles on a 20 limit & in the south, south of the Black Mountain (which has it's own ridiculous speed limit issues) there is ribbon development of a number of towns on a major A road for about 10, maybe 15 miles - a 20 limit has been slapped on the entire thing.
Add to that the signage - which was appalling for "Safety" signs...