Yes, we stayed there 3 years ago (see my trip sig.) and absolutely loved it! The hotel itself is top-notch all the way, but not "hoity toity". We stayed on points and took a mountain view room. While I'd LOVE an ocean view room there, we weren't in our room during daylight hours much anyway. So I'd probably go for a longer stay in a lower point room, instead of a shorter stay in a higher point room.
As disney gadabout mentioned, the grounds are breathtaking. We loved strolling all over the place and just taking it all in. The memories are still vivid for all of us. We relive it pretty often.
On-site restaurants are very pricey, so we only ate on-site once or twice. We had simple breakfast stuff in our room, and otherwise ate off-site.
Service was friendly and attentive. Lots of special touches.
The resort is somewhat "isolated" from nearby towns, so we were glad to have a rental car. We did plenty of exploring, shopping, and eating out on our own. But our best touring of the Big Island was by way of a Circle Island Tour. It was a full day of guided touring, and we totally enjoyed it.
We would love to go back to the Mauna Lani. It was a splurge with points (we stayed for 8 nights), but completely worth it to us.
