I built the Tamiya I-400 about three years ago and it is Tamiya at their best. With careful clean up of sprue stubs and a bit of care the entire model pretty much snaps together. The photo etch for it fits well and adds the necessary detail you expect to see. The finished model is pretty stunning for something so small. I posed mine with one plane on the cat and the hanger open with a second plane being moved forward. Painting it takes longer than assembling it, that's for sure. I'd suggest adding at least a few sailors to it so there is a better idea of scale because this thing was HUGE for a sub.
Oh, and despite the painting instructions the planes were silver dope and hand painted US markings when she sailed on her final voyage. They were all launched into the sea before she surrendered to US ships, but the crew clearly stated that the planes carried US markings.
As for stashes, I can't comment. I have about 400 in the stash and about 200 built. At this rate I'll have to live to 178 to finish what I have but I keep finding new models I just have to have! Yeah, it's a sickness. But fun!!!