I see that a new bookshop that’s just opened hereabouts has the Oxford Grammar of Classical Greek and the Oxford Grammar of Latin. Does anyone have any comments on/experience with these works? Should I be fighting my way through a mob of frenzied classicists to make sure I get my copies?
They are good. They’re rigorously grammatically but devoid of any of those irritating archaisms you might get in old grammars.
For example, the Latin one proudly has no ‘v’. It sees itself as a successor to Kennedy’s Latin Primer. It’s laid out nicely and gives non-pretensious explanations of things in modern english. It also quite a few useful appendices, including even “tips” and “commonly confused words”.
Hey, hey, hey! 
I spend much of my time with those irritating archaisms!
So, I still have to use Smyth or specialized grammars for things not in Attic. For Attic, though, the Oxford Greek grammar is very good: compact, clear, complete on the fundamentals, and easy to use. And lighter than Smyth, so helpful for panicked searching for forms of ἵημι on long airplane rides.