When I first started getting into make up (10 years ago) i used to have quite a collection of these pigments. I had all different shades but clearly remember falling in love with the Cornflower Blue, it was my absolute favourite. I used to use these with no primer (back in the days before primer was a thing) and these still lasted all day. Very very pigmented, you don't need to use much to get a stunning eyeshadow look.
I haven't repurchased them since as it was relatively challenging to purchase (before the new stores existed and I brought onine and got it shipped to NZ) and I find it too pricey. It is a great quality product but I believe I could get similar results for the fraction of the cost.
I got some mac samples online they are very great in terms of pigment but some shades are not as finely milled and so they do not stick as good or go on as smooth as others there are other alternatives and pigments out there that are cheaper but some times it can be confusing as they may just be loose eye shadows not concentrated actual pigments if you shop around though you can get some shades that are just as good as mac and way cheaper. I have found out that mac made the container smaller so you get less product but the price has no changed favorably which is not very fair on its customers I have tan melon and a copper type pigment also deep purple they go on nice and look foiled wet because they are not the glitter deep purple didnt seem as fine milled as the others my suggestion is if you have a big use for pigments and they actually do have a few uses besides eye shadow then pick some staple colours and I suggest you can try and mix them to create secondry colours because mac is expensive. Apart from the pigments I really have not tried mac make up but its popular. I do not really favour because of the price and animal testing. The packaging has changed and got smaller not good and some have stoppers and some do not apparently so if you spill it thats a huge waste. The colour pay off is pretty good. Some can actually streak or cake though if applied wet or without primer