Chiming in with my $.02 worth on the differences between West Maui (Lahaina/Kaanapali/...) vs South Maui (Kehei/Wailea/Makena). I prefer south Maui because it's more reliably clear and sunny. Well in January-March, anyway. The last time I stayed in Kanapali the wind never dropped below 20 knots, it was cold and mostly cloudy. Yuck, not my idea of a winter vacation from the Seattle rain. Saw lots of whales from the hotel, though! On the other hand, the last 4 times I've stayed in south Maui, it's been warm, sunny and fairly calm. We did have a friggin monsoon one afternoon last week but the entire island got drenched. Lahaina feels a lot more touristy than Kihei. I've been going to Hawaii since the 70s (got a NAUI cert on Oahu decades ago) and seem to always go back to the Kihei/Wailea/Makena area.
Lots of really nice restaurants in the Kihei area, too. On the latest trip (last week), my GF talked me into going to Cafe O'lei in Kihei (I hate gimmicky names) and it was surprisingly good with decent prices. Way better than I expected. Will definitely return.