Honestly, the samples aren't all that great in any part of The Score (and even The Orchestra is mostly only decent sounding considering the small RAM footprint). That's where the marketing of the library as delivering production quality material is really on the verge of passing from marketing fluff to being dishonest.
But I would also say the samples don't need to be great sounding in that sense for what The Score as sketching tool requires. They need to be adapted to the needs of the engine: sounding ok in an arpeggiator, sounding ok being modulated with a volume envelope, being small enough in RAM and number of samples that you can load lots of instruments into a single instance of Kontakt so the engine can work on them. Mostly the samples for the ensembles succeed at this task. Some of the samples they delivered for the melody part of library though are hair-raisingly poor, so bad you can't really even use them to make a guide track. And the legato is often simply atrocious, maybe the worst I've encountered in a commercial library.
The problem with the ensembles part of the library is that it is also not set up well to be used. It really expects you to use their presets, which would be fine if they were good, varied, and there were a lot of them, but none of those things is especially true. There are a few good useful presets, but not enough of them, and too many of them sound more or less the same. Ultimately there isn't all that much there despite the boast of however many presets, and rolling your own presets is not simple because the interface isn't set up very well to do that kind of work. Then if you actually do it, the browser doesn't really allow you to organize your presets very well. With luck—if this is indeed an essentials version of the score—they have managed to put some thought into organizing user content, since at least that is relatively easy low hanging fruit.