Dismissive service is a common complaint when it comes to France (or other EU destinations, especially during high season). In general I dislike European service standards (or lack thereof especially during high season). There are exceptions of course. A different discussion but worth mentioning is the fact that I have seen too many times that dismissive service generally starts in France when staff is required to speak anything else than French. I am bilingual so not an issue for me but still find this repulsive.

Best on the coastline? Per your opinion? Eden Roc has a massive beach like no others (IIRC the ones you mention don't even have one?). Food is a highly subjective matter, not to mention that the South of France has more options to dine out than I could possibly think of.

I have never encountered dismissive service at Eden Roc and the food (but we tend to dine out) was more than ok for my standards.