I never had any major issues. not fibre to every property (like Andorra) but ok. Anything from 10mb to 30mb, there is an area in the North of the island which is a massive development project called Mont Choisy Smart City, I believe all properties on this project have full fibre... IF we moved there full time this is probably where we would live.
https://www.montchoisy.com/en/smart-city
You would be surprised how developed it is. What took some getting used to was very modern 1st world directly alongside 3rd world, my wife would visit a spa which was surrounded by dilapidated falling down buildings but the spa was first class and a third of the price of the UK. See below links to just a couple of the malls, with more being built. You can shop 'almost' European / South African with many international brands. Prices are ok but it's an island so very heavy on Imports, fresh (European) fruit & veg which is not grown on island is expensive and not great quality, biggest downside is the price of alcohol, wine is very expensive, spirits work out cheaper, and local beer is ok. French is the No1 language but English is the 2nd language so all signs are in both languages and 99% of people speak both so things like paperwork are no issues.
https://mahogany.mu/https://www.ascenciamalls.com/