Many of the JDM engines sold in Japan are very similar to what we get here. As already mentioned, the JDM FS-ZE is identical to an FS-DE, aside from the pistons, camshafts, and tuning.
The big short coming of this engine is the oil burning, which is a side affect of low tension rings. This was not limited to Mazda, the whole industry began using them to increase fuel efficiency, and many manufacturers are still dealing with oil consumption today.
Otherwise, you don't see many problems with these engines.