The new opera gx layout is a bit annoying to get used to especially how everything is smaller. yes that does give more space for the main window but I would prefer it if you could either choose or customize it more. while having this new layout like this is indeed more sorted based on category but I would still like to have the option to have the tools as they were and larger.
a positive change about the new layout is this setting bar. it's much more intuitive than the old way too navigate the main settings and such