The SMS version is the definitive Golvellius experience. It's basically a totally different game from the MSX1 version - with completely new maps, new dungeons, etc. However, a lot of the rough edges of the mechanics are gone. This is for better and for worse. The boots that grant you iframes are gone - you get iframes by default in the SMS version. Probably better 'game design' (by today's normative fun-centric standards), but less interesting. Still, the world is more fun to traverse, the dungeons are tighter, etc.

I do wonder what is lost along the way... Although I think the SMS is the definitive version, I mourn the creativity and experimentation of the MSX1 version. I yearn for those rough edges from time to time. We don't see enough of them these days.