Got back from our trip to Maui last week. We stayed at the Kula Lodge for one night to be as close to the crater as possible to see the sunrise. We stayed at the Westin Resort in Kaanapali most of the time, but for our trip to Haleakala, we stayed at Kula Lodge, which is the closest lodging to the crater, I believe.
I think the mixed reviews are due in part to which room you end up in and which staff member ends up helping you. We booked Vista Chalet #1, which is a spacious room with nice views and comfortable beds. We had no problems with traffic noise. The night manager who helped us was nice and helpful. I understand some of the reviewers had parking lot views and encountered poor service, unfortunately.
Also, for some, it's a matter of expectations, too, I think. There are no TVs, phones, because this is not a resort. It's a mountain lodge. I wouldn't use Kula Lodge as a base for a weeklong trip--as a family with kids, we wanted to explore all of Maui and do mostly beach activities, so most of our stay was at the big resort with fancy pools in Kaanapali. But for one night, to avoid dragging the kids out of bed at 2 or 3 a.m. for the long drive to Haleakala, Kula Lodge was adequate. It was comfortable, clean and charming. Just make sure you book the right room and hopefully, you'll get the rightstaff person to help you.