I think it really depends on the preference for eyeshadows.
As someone said, the testers tend to not swatch nearly as well because every person is using their fingers to try them. So their tends to be a coating that builds up on the shadow effecting the pigmentation. Also fingers never swatch as well. I usually will take a tissue and wipe the shadow and use the powder on the tissue to swatch the shadow on customer's hands. You'll get a much better feel for the colour than with your hand.
Also, I might be in a minority, but I actually like that MAC shadows don't just go on full out intensity all the time. I prefer to have a solid shadow that has good pigmentation that is buildable in intensity. It gives me a more diverse range of options for using the shade in different looks. Again, that might just be me. I tend to like a lot of the shadows that the blog community doesn't care for. (ie. I love my Quite Cute quad). However, I also like other brands beyond MAC as well. I have a small selection of Urban Decay, Too Faced, Make Up Forever, and TheBalm. Personally though, I find the quality to be the same as MAC. But personal preference plays such a huge part in make up selections.
