I've been learning a lot recently and revisited my approach lineup. I just added the A4 back in again. It definitely seems like it could be a polarizing disc based on handfeel: I tend to like chunky, rectangular, and flattish rims just like this one. Its rim is unlike anything else I own. It's the most comfortable slow disc I own for approach forehands for my square meatpaw (vs. Harp, Zone, Pig, various mids or putters).
Among other approach discs, I tend to bag the Zone the most, but I started taking advantage of the slightly more neutral flight of the A4 now that I have better angle control. The A4 will carry forward a little more than my Zones and still fade reliably, and it still fades pretty hard within 150'. As it gets out to 200'+ it seems to show its turn, but it still fades back when thrown well past that distance and it doesn't really risk a turn-and-burn unless I give it significant OAT.
I really like the A4 for up to 200' and closer. I've experimented with it on high lines of attack with baby anhyzer stalling shots that drop onto the target, low straight forehands, and more aggressive anhyzer and hyzer lines. It feels like it's very true to how it is thrown (not a meathook), with just enough overstability to make it fit a versatile approach role. I might worry about accidental torque on forehands (mine is still developing), but I tend to use it for touchier, mostly straight forehand shots 200' and in, and it does great w/ just enough overstability to make me confident unless I'm being pretty sloppy.
I feel like my 400g A4 was maybe closer to 4 4 0 2.5 out of the box, but showing signs of wearing into its 4 4 -1 2 stats, which would be great. It fills a gap right between my mids, putters, and more aggressive approach discs like the Zone. I'm noticing I can use the A4 to shave strokes here and there and hit a few lines especially when the Zone might fade a little more than I need, require more power, or risk skipping - the A4 is a little more shapeable and seems to like to *splat* more wherever it lands. The Zone tends to come out when I need more late fade, distance control at a longer range, a baby skip, or have a more significant headwind.
So, the A4 seems like a disc I don't hear a ton about and might be redundant/polarizing for some people, but I'm really glad I added it back in.