I haven't built one, but I owned one of the kits for a few years (traded it away for a rare rocket kit I wanted).
It looked nice, although some of the proportions in the box seemed a bit odd and the flexible nature of the vinyl with some of the parts requiring a bit of de-warping had me shying away from wanting to build it after I acquired it.
Come to think of it, I don't ever recall seeing any modeler finish one of these (except maybe in Japan when they first came out).
The biggest Excelsior kit available was the Lunar Models version supposedly close to the scale of the AMT refit. But this ships scale is often debated. This kit also had so many issues that the only accounts I've read equate the build with scratchbuiling.
The AMT is smaller than the Tsukuda and IMO doesn't quite get the bottom hull quite right to my eye.