First, I would like to point out the image here shows four carts mounted in-line, all on one side of the case (I believe this is a newer version). I have a different version of the case, which has two on either side, on the ends, opposing each-other. I own a few different Shure products, and all-in-all I like their company/products.
At first, I was thrilled with this thing; it has a rubber gasket that keeps dust, liquid, etc, out (as far as I can tell it's air-tight). It's got a nice, solid plastic shell - feels very durable. I am a DJ, so I throw this thing into my backpack, and take extra mounted cartridges as backups. However, after I mounted my carts on the headshells in the Baerwald alignment (in this instance, that means they are towards the front), the carts are so far forward they hit the opposing pair when you try to close the case!!! I am using SHURE M44-7 CARTS WITH TECHNIC HEADSHELLS (the most common headshell/cart combo). I also have a Shure M97xE cart, with the same problem.
Just to be absolutely clear: the purpose of this case is to store and transport pre-mounted/aligned headshell/cartridges. If ever I have a needle issue, I can swap them out with the ones from this case in about 10 seconds flat. If I mounted the carts further back on the headshell, they would be out of alignment, making the purpose of this null. So, this "4 headshell case" is actually a 2 headshell case that takes up the space of a 4 headshell case. It's as though Shure went straight from the drawing board to production with no R&D in between.
Pros; sturdy construction, holds headshells securely, air-tight
Cons; case is too large to only hold 2 headshells, case is too small to hold 4 mounted and aligned headshell/carts, falsely advertised, price
This case gets 2 stars instead of 1 because there is nothing else - that I know of - that is better. HUGE bonus points would have been scored if there were a place for spare styli.