I am shocked at the low scores from previous models. Maybe I just have low code standards but I've generally been vibe coding since 4.6

4.6 had functional but very poor quality code

how so? it has been my daily work horse,in fact so was 4.5 BUT as long as we steer it IT does a good enough job. I have not tried Mythos/Fable yet SO do not have an opinion on it.