i'd not give up my windsup over an LT if the focus was waves. my windsup is the board i take away for camping trips. surf when there is no wind and add a 5.6m when there is wind. the LT can't touch it when it comes to surf.
on the other hand if i'm sailing lakes, open ocean and bays. the LT is real hard to beat. it's also easy to rig and very quick to get on the water.
you need both.

the exocet wave longboards were the middle ground. flat water, waves, they plane early....... pretty much what you are looking for but they aren't made anymore.