As a perfumer I agree with the animal cruelty factor. I would never use natural musk, civet or castoreum. There are such good synthetics. In fact, chemistry has given us a huge variety of synthetic musks all with different characteristics that we don't need the natural. Natural musk has a bit of a fecal note to it, which isn't always bad for orientals, but that can be added with other ingredients, if desired.
Also, I agree with the writer who said that ambrette seed oil or absolute is an inferior ingredient, although it is the only plant musk available to the "natrual" crowd. It has a large lactone ring which is musky, but the extract is overshadowed by a lot of fatty acids and fats that can get rancid. It's just a lousy musk. In my opinion the nicest musks are the large ring ketones such as muscenone, muscone, and a slew of others. Good large ring lactone musks are Ambrettolide, Exaltolide, pentadecalactone, and similar. VERY common is Galaxolide, which is a totally different structure known as an isochroman musk. It's cheap, but smells good and lasts. Then there are the nitromusks, which are inimitible, very luxurious and voluminous, but are now restricted to .7% of the oil part of a frag. This is one reason why some older frags are no longer on the market. A crying shame, as it's never been proven that the nitros cause any damage to life forms, only that they don't break down easily, but neither does Galaxolide and it's NOT restricted. Oh, that will probably get restricted, too, one of these days. Go figure.