We are going to mauritius and I have done extensive research, from that, in my opinion the west is best, and september, october or november are the best months, it is cooler then (average temp. around 24degrees but it does have cooler evenings) and less rain, the east can be rather breezy due to the trade winds, the west is sheltered and has amazing sunsets.
For a small intimate resort look at Sands, this is were are going to book.