I really wanted to keep the A440 when doing the HZ-T swap, unfortunately all the doodads that make it extra beefy were getting the tag for the A440 up to around $5000, while the used H55/split case were about 1/3.. easy decision with the costs of the engine and turbo setup involved.
The A440 is an incredible trans. I did a lot of Moab in 2wd just with the control I got. Did McGrew in 2wd, and basically got to the point that I would test myself that way because I was able to point and shoot effortlessly over what I could do with manuals (the '79 40 had a 420/3spd case, the '81 BJ42 was stock but the 3B makes wheeling easy too).
The other benefit is you get a bigger OD over an H55, along with a doubler kind of effect in low range with the torque converter. All it ever needed was more power behind it so the truck could get out of its way. Lynchmob still wants to do an HZ/A440 swap and we had most of the pieces figured out (unless you got a combo already in place.. not sure if just 12H-Ts were setup for auto, it has been a while).
That all said, I love the H55 with the HZ. 1st gear for puttering around backcountry bush is simply awesome. It is a great combo, but both Kevin (wagongear) and I have lamented not having a taller 5th.. we could use an H66F, or maybe a Mark's gear OD in the high gear ($$$). 4.11s are the ideal with 33s so that isn't really changeable. The A440 would have been perfect had I the money to do it at the time.
I think it and the A442 are the most underappreciated fantastic Toyota products they have released. They just paired it with the wrong engine (in the US, heh). I have driven a 13b-t/A440 FJ62 and it was a total blast that put you back in your seat.