The trems are also very differently made. The AVRI parts are pretty close to the vintage stuff - solid feel, smooth action, good spring and a tighter bar feel/travel. The Jpns stuff is more lightweight, feels flimsy by comparison, and the trem stop seems to function on only about half of the MIJ/CIJ guitars I've played. Keep in mind, if you're only used to playing the Jpns models, you'll probably not have much to complain about. The casting/stamping is a lot cleaner on the US-made part, and there is definitely a heftier feel. The AVRI is on the left, MIJ on the right in the pic below:

If you're comparing them side-by-side, there's a noticeable difference. It really comes down to personal preference, but I'd replace the unit myself.