I'm not an expert clarinetist -- I've been playing for a year or two now on a beat-up plastic clarinet, so take all my thoughts here with a grain of salt.
COSMETICS: This clarinet is aesthetically so pretty. The material is much nicer than ABS/plastic. It looks great. The mouthpiece is plastic and has a small amount of excess material which I easily removed.
MECHANICS: Keys work well, smooth, no leaks or anything. It IS difficult to assemble, even with cork grease, so I plan on leaving it assembled on its stand (which came with the clarinet) most of the time. I assume it'll get a little easier to assemble with time. Ligature is as expected.
SOUND: It sounds great to me. The tone is much warmer than my previous ABS clarinet, and the intonation is also much better, particularly on high notes. I am able to play smoothly, move between registers easily where on my ABS clarinet I could not easily shift registers or jump large intervals without squeaking.
Other than that, it comes with some reeds, cleaning materials, gloves (which I'll never use lol), a music stand and clarinet stand, which is all great. :D