It was 11A that led me to (a hint) of the theme and then it was still a while before I managed some themed answers and confirmed it.
In general I don't mind themed puzzles - as long as the answers aren't too obscure. I would have regarded this one as reasonably 'mainstream'
The months one a week or so back I found surprisingly difficult - not helped by me taking ages to cotton on to the theme. Even when I somehow found out that there were 12 I spent some time unsuccessfully trying to fit signs of the zodiac in