Having stayed here twice, this is my 2 cents.
Our first trip was 7 nights and we felt is was too short, especially given the distance travelled to get there. Our last trip was for 8 nights and we still did not want to leave. We just booked our next stay for 9 nights late this year and hope it will feel sufficient.
As others have said, this is not a large resort so if you need activities to keep you busy, it will ge boring, that is just a fact. I can snorkel everyday here and never feel like I have seen it all. We also enjoy doing the basic Maldivian fishing activity and eating our catch once or twice per trip. That is about all we do for activities besides just sitting on the beach or room balcony and we never get bored. I think the length of stay is extremely subjective so if you can deal with solitude for 11 days go for it, otherwise as others have mentioned, break the trip up.
BTW we are also coming on AA miles and normally choose Cathay so we can stop somewhere in SE Asia. Same amount of miles for First class as it takes to go business through the Middle East. For our next trip, we are going to spend some time in Thailand before continuing to MLE. We would stay longer in MLE but sadly cannot afford another 4-5 days!