I fly 190's a lot, particularly the A8. As a matter of course I try to keep my speed up so I don't use flaps except in rare instances, and rarely more than one notch when I do although there have been times I've dumped all three notches.
I believe in the fight with waystin I was using flaps to haul the nose around and try to stay inside him and probably had all three notches out. Even though I was commited to the turn-fight I ended up extending 1-1.5K three times to re-gain E and re-set the fight. That was one heck of a fight. waystin.
The 190's turn better than people give them credit for. In a slow turn fight you'll feel it start to wobble near stall speed, and to turn any tighter you'll need flaps out. Once committed to this there is no going over the top. If you intend to extend for a re-set remember to get the flaps back in to start building speed/E for the extension.
A better tactic in the 190's is to keep your speed up and use a vertical zoom, then roll 180 degrees, yank the stick back and drop back onto your opponent. This utilizes two of the 190's strengths, it's zoom capability and it's high roll rate and doesn't force you to lose speed getting over the top.
I've beat many more nimble planes turn and/or E-fighting with the A8 (Spits, F4U's, F6F's, Zeke's, Hurri's, etc.). All it takes is one shot opportunity to win.