Don't know if you meant specifically in the Jazz; I've never tried one there.
In general, though, I think A4 doesn't reveal its true nature until you play it with some volume.
I concede it can sound and feel pretty meh in the livingroom or bedroom.
But at band levels the sweetness comes out and it gives a nice vintagey fingertouch.
I'd fully intended to swap out the stock A4 mags in my McCarty pickups; was quite sure they were less than okay.
Then I played them at stage volume and realized they're actually great.
Glad I gave 'em a fighting chance before I pulled them.
I have a set of A4 Wizz PAFs that behave similarly. Played quiet they're good; at volume they're downright epic.
To me when played loud A4 almost has two different characters, sort of a split personality.
At low to mid levels of gain it's sparkly and fairly tight - almost dry, for lack of a better word.
Then when you give it more gain the highs smooth out and the mids go liquid, almost as if you redialed the amp.
Pretty cool effect.
Full disclosure: my entire personal history with A4 is limited to those two sets and one A4 in a 59N.
So it's possible the qualities I ascribe to it aren't genuinely universal.
Still, based on my experience, I say try it at battle volume before you write it off.