We only started going in 2008 so I don't have the past to compare it to... My husband's grandpa came with us to Maui for our wedding and felt the same about how much it had changed. We've been to the four larger islands and Lanai, but still prefer Maui. Likely because it was our first? It just feels like a nice middle ground of some busier areas and some quieter... we didn't really have expectations besides nice beaches since its still the US. We certainly still felt "island time" though. We usually rent a condo in Kihei and have a great time every time, its not expensive at all. Oahu was too busy for us also - getting out of Honolulu can be a pain as is parking.
FWIW we've been to the Cook Islands and French Polynesia as well - Hawaii still has a special place in my heart. Bora Bora is what I would call way oversold, but I'd happily go back to other islands there too.