Picked up a box of mangos at the Costco in Santee on Sunday. These are without a doubt some of the best mangos I've had in the U.S. They are HUGE, succlent (the only word that can describe them), sweet and unbelievably good.
I do not know what variety they are as the fruit sticker only says "MangoPro" which is the packer, not the variety. These are also some of the largest mangos I've ever seen, each one weighs in at about 2 pounds. The pit is narrow and small, meaning you get a lot more fruit than pit. There are 8 mangos per box and I think it cost around $10. Some of them appeared fairly green, but are not rock hard. They are ripening quickly and have a slight "give" when lightly pressed. So don't let the greeness of them put you off or think that they won't ripen.
If you're in Santee, have a Costco card and love mangos, stop by and check them out.