Hi wisew,
Congratulations on your new mattress 
All the options you mentioned would have made great choices and final choices are always difficult when you are looking at “good vs good” and there are no clear winners between them but FWIW there are many forum members here that are very happy they chose the Alexis which is a high quality/value mattress.
In my experience … the after sales service of Brooklyn Bedding is among the best in the industry and like the other members here they go out of their way to work with their customers who have any reasonable issues to make sure they are happy with their purchase. I think that you will find that in most cases the few “negative” reviews you will find with better manufacturers such as Brooklyn Bedding are either from competitors who engage in this type of practice to harm the reputation of their competitors or from customers who have more “unreasonable” expectations or issues.
Phoenix