This turned out to less fearsome than it looked, though I will admit to having some problems completing the NW corner. I'm not all that keen one of the down clues in that sector, which seems distinctly non-Ximenean. After filling the grid and studying the grid for ten minutes I spotted a few things but no coherent theme, so put it aside and looked at it afresh this morning. Another five minutes of experimentation got me there, so it was not the agonising endgame that I had feared.
I confess that I found the theme a tad disappointing, but that's just a matter of personal taste. I'm sure some will be delighted not to have to research some arcane topic on Google. The puzzle was very well constructed, with a well-sign-posted route to the conclusion and several PDM's.
I can't say I like the new design of this site. It displays far fewer messages on one page. Why do people fix things that ain't broke?