can't speak to pricing, lepmd, but we've stayed at all of those places except amanera and herm bay. multiple stays at samanna, jade mtn, and cap juluca.

of all the ones you name, i'd put cap juluca and jade mt at the top of the list. then the choice comes down to whether you want to be directly on a beach or not. at juluca you are, and one of the finest beaches in the caribbean to boot. at jade you're re not. of course, but the hard product and entire experience of jade is certainly more singular. i'm not sure what's up with ladera these days, but as recently as ten years ago it was still a very special place. the rooms are not nearly as insanely well finished as at jade mtn, but the views were the equal. ladera pioneered that 'missing fourth wall' thing that jade has taken to next-level, and there was also something very nice and authentic about the
rustic-ness of the rooms there. last time we went we had one of the larger rooms with the pools and it was pretty darn great. (prolly circa 2013).

we stayed at sugar beach just before the viceroy refurb. can't say i love the viceroy brand in gen, though the flagship santa monica location can still be fun for a drink, and the playa property is small, special and pretty dreamy (kind of un-viceroy, frankly). and it doesn't look like they've done tons of new build at sugar beach, though the accommodations have clearly been upgraded, ultra-refreshed. (they needed it) when we went it was called jalousie plantation, and it was sort of a disaster. i think it was branded as either a hilton or conrad property, and the service was almost non-existent. felt too large - both in terms of size/spacing-out of property and crowds at common facilities. nothing was really walkable from our casita, and mokes seemed to do the circuit about once every hour. lots of waiting around. also, the beach.while ample and picturesque, lookes to have about 80 billion truckloads (conservatice estimate) of blinding white sand dumped on it. poorly, too, as there wasn't enough to cover the natural dark grey sand beneath it. viceory has hopefully stopped this ridiculous practice, it felt sooo out of place (almost sacrilegious) to do that in one of the western hemisphere's most jaw-droppingly beautiful locations (between the pitons).
that made us really wish we had gone back to anse chastenet for that trip, where the beach is equally gorgeous and all natural. not quite black sand, but a darkish grey. (not sure if chastenet is still going - same owners as jade, i believe - but it's the same beach accesable to jade).

samanna is lovely. i found the beach a bit underwhelming (especially since you're forced to gaze longingly back at juluca/maundy's on anguilla) and the place a bit overpriced in gen for what it offers. if i were choosing between samanna and either jade/juluca/sugar beach, i'd go either of those latter three, personally.