If you look, I'm not doing too badly in the WWI arena, flying exclusively the DVII. Is it harder? Yes its harder, I actually have to do something other than turn circles. But I also see that the performance and structural tolerance differences are small enough that E-fighting is only marginally effective unless done PERFECTLY.
The parametres are different in WW1 think inches instead of feet, think thrust instead of zooming, the hardest plane in WW1 to fight and fly in is the F1 Camel I would rate it the hardest in the whole game.
If you need to go vert and stay out of guns use a climbing spiral to the right against gyro planes. Another thing against the gyro planes DR1 and F1 if you have to flat turn, turn to the left, a lot of the better DR1 sticks still turn poorly to the left as they fail to keep the gyro effect in check.
Something has changed since last year.
The only FM they changed since the arena started was that of the DR1 your probably just getting better
