Hi Chris,
I think you will be more than happy with the plantations estate. My wife and I stay at the Hilton and the bars there ( Palm court lounge and the Robinson Crusoe pub) are both good. Depending on occupancy they can be busy or quiet. The food in the Coral Reef Restaurant at the Hilton is excellent and there is a buffet each night in the Plantation Room.
With respect to the rest of Lowlands, since you have a jeep, you are not far from anywhere. Turn left out of the Planatations onto the highway and you are only two minutes from Crown point and all of the shops, restaurants and hotels down there. Turn right and you are 5 minutes from Scarborough.
The restaurant reviews on this site are all spot on, and again, they are all within striking distance.
The beach on the estate is on the Atlantic side, and is consequently a bit rougher and windier than the Caribbean side. The upside of that is that there is always a nice breeze to keep things a bit cooler. The beach is long and you can see pictures of it on the arial photos section of this site - pictures 20 and 21. The water temperature is fine!
Hope this helps.
Have a great holiday
Grant