I have never been there. However, I learned a lot about it from the Seychellois I met and also met a lot of people from Mauritius while in SEZ. My impression is that Mauritius, though apparently quite pretty, is less of a "paradise" and more of a "real" place.
The people seem to genuinely love their country, however, many come to the Seychelles for vacation. I think aside from the favorable currency exchange, that does say something. I also seem to remember some folks I met snorkling say their beaches weren't as nice in Mauritius.

Personally, the next trip I take to the area would be to the Maldives (or back to the Seychelles). Hope that helps.