I've found Sol 6.1 a regression over 5.6.

Not due to capability per se, but writing style and polish is much worse.

It will leave really bad comments in the code, commit messages etc without strong explicit steering. Though I've basically moved away from having the model write any documentation at all.

It also tends to talk very circuitously and referencing things implicitly instead of just being direct and clear.

Certainly it's more capable in debugging, but I much prefer Astra over Sol now.

Of course, Astra has its own problems of code golfing everything. But at least it's very concise and direct