We've done Kauai and the Big Island, both of which are spectacular.
We have cousins who live in Oahu, but for whatever reason, we seem to always pass over that island (oh, right, because we don't want to vacation with the population...).
We're going to Maui strictly because the wife is going to a conference, which only takes place once every two years. It's a specialty conference - there aren't many others like it. She typically presents at it, but this time she's not (she just started the residency - in 2 years she'll present again). The last time we went to this conference, it was in Napa, CA. Next February we're supposed to go to the orthopedic conference in Breckenridge, CO, but it'll be beyond pricey...
Any way, when researching Maui, I didn't find things quite as amazing as the other two islands we've been to. The hikes seemed tame, the remote region of Hana is, as aqua notes, "meh". It's a nice resort island, from what I read.
...but vacations are what you make of them. Renting a convertible for us is a treat, as is being somewhere that you can actually keep the top down. FWIW, the convertible was $5 more than the most basic economy car (a Nissan Versa Note most likely) - why wouldn't we want it?! Wranglers are the expensive vehicles to wrent there - they wanted $1,000 more than what we're paying.
For us, hiking on the volcano and getting off the grid in Hana for 3 nights in a tiny home are the highlights. The conference, at a Fairmont, will be lovely...but meh. That's a means to an end. The last few nights at the Westin will give us some relaxation...but meh, a beach is a beach.
I'd go back to the Big Island of Hawaii and spend a week in Volcano National Park. What a place!
