I've stayed at both, and we own at Maui Lea.
The one plus for Kuleana is that it it right on the water. It's not a usable beach, but if you're lucky you might get a unit where you can hear the waves. The units are small, and dark.
Since we own at Maui Lea we are prejudiced. We LOVE it there. In fact we'll be heading there in a few days for a two week stay. The units, even the one bedrooms are roomy, with a wonderful lanai.
The other thing to consider is that they are on totally different parts of the island. Kuleana is closer to Kaanapali and Lahaina. Maui Lea is in Kihei.