The stock speaker in my Delta King 10 wasn't bad, but I wanted a more focused, clearer sound, reminiscent of old Fenders.
Replaced it with a Jensen C10R initially which I found too harsh in the highs and too mid focused. On top of that it farted out on the lows quickly, especially with tube overdrive. In fact, it sounded like an 8", a bit too Champy -- nothing wrong with that, but not the sound I was after.
The C10Q however fits the bill perfectly. Clear highs but not piercing. Well defined midrange, great with overdrive. And the lows stay well controlled even when pushed. Exactly the sound I was looking for. Now, the Delta King is perfect.
(Or, it would be if it had a tremolo, but that's beside the point ).
In conclusion, great option for that classic American sound -- more SIlverface than Tweed.