I started with enter the pit box. Pretty good punk and hardcore music. And then I wanted to try the metal box, so I switched. What I like about those boxes is that I have been introduced to a lot of bands that I didn’t know about and I really fell in love with some of them. I usually get 4 cds per boxes and it also come with some goodies (patches, posters, etc), so I feel it’s worth my money.
Just one thing to be aware of about the metal box is that sometimes not all the cds are metal music. It can also be hardcore, rock or else. I believe it depends of what their providers have in stock. Luckily for me, I am not listening to metal only in the rock family, so I am fine with it, but if you really are into metal only, there might be some months where you are disappointed.
In conclusion, I recommend the Moshboxx. It is my highlight of the month.