I occasionally dable in the the jugs, but im not a specialist in them by any means. But you have to firstly realise its not really a stall-fighter, never will be, so unless you have no other alternative, just dont try it. The jugs shine up high. The D40 has better climb rate than a D-mustang above 11k, and just seems to handle nicer. Its instantaneous turn rate is very good and it seems to hold E very well up high even through short-duration high-G turns. Just keep a good head of steam up and keep the fight nice and fast, and the jug will give a good account for itself.
Learn its weaknesses too. Its not a stall-fighting tail-chaser! Its outclassed by a lot of crates below 10k, and she's not the fastest. It will never compete in climbing contests with nearly anything either. Zoom climbs are another matter tho.
The D11 is the most nimblest, and the fastest D model on the deck; but its the worst climber of all the Jugs. The razor back obscures your view a bit too.
The D40 is the best climber of all the jugs, and turns fairly well compared to the N model.
The N is the fastest hands down, and has *HUGE* range. The D40 outclasses the N in the climb/accleration contest, but i find the N is the more "survivable" jug. The range on it allows you time to engage when you are good and ready, and slip away to reposition and re-enter the fray at will many times over. Ive landed 12 kill single-flight sorties in the N model doing this.
With the jug you really need to be able to engage when you're ready (eg got some smash and/or alt) and pick your fights to maximise your sucess rate. Its not the best at saving your butt if you stuff up, so get it right up-front (mind you thats good advice for any a/c). Try find the fights up high where the jug is in its element. As a last ditch move, a power-dive to the deck can be useful dislodge enemies or cause them to auger if you time it right - follow it up with a low-G zoom climb and a hammerhead reversal and spank the floundering idiot below you with those 8x50cal 'shredders'
This works brilliantly against japper planes like the Niki and Kis etc, not so well against a spit 16 tho. 109s and P38s if they're dumb enough will just auger, so you wont have to worry about a hammerhead.
I set my convergence in the jug at 350 - all 8 at 350.