Is it good for couples and motion isolation?

Yes, though it is the bed's softest axis at 7.6, still strong in absolute terms. With no springs, a partner's movement arrives heavily muffled. It does not score higher because latex is naturally springier than memory foam, so the same liveliness that makes it easy to move on lets a touch more motion travel than a dense memory-foam surface. Most couples sleep undisturbed; only the very lightest sleepers might notice the latex bounce.