Explorers are rare and special guitar types; that being said, it's normal that there aren't loads of options when choosing a dedicated case (i.e. not a generic, universal case that you should customise for your beloved EX). And if you are buying Epi, you are clearly not in the Gibson-budget range, so at the time of buying I considered this the best option on the market.
Considering the above, my general opinion on this case is that you get what you paid for. Nothing more, nothing less.
Bought this from Thomann about 4 months ago.
The outside material is some hard plasticky thing which seems solid enough but slightly flexible, so I trust it won't break unless really abused -- which I don't plan to. The inside is a mix of plastics with what I believe to be some plywood under the padding. The entire inside is padded.
To give you a size estimation, you can fit two A4-sized papers (or songbooks, for that matter) side by side in the compartment under the guitar headstock. More on that on my last point below.
Pros:
1. good build quality, nice materials, looking sturdy enough for the consumer usage (i.e. storing it at home, transporting it in the car, playing gigs with friends);
2. the Epi EX fits *PERFECTLY* edge-to-edge and is held perfectly in place both vertically and horizontally;
3. the covered compartment under the neck of the guitar is very large and nicely padded all around just like the rest of the case, and closes neatly under the guitar;
4. the handle is positioned off-center so that the case hangs parallel to the ground when you load in the guitar, two cables and 2-3 MXR pedals.
5. you can't really see this in the pictures, but the case has 4 stubby metal legs on the underside and 4 more on the "back" side so that the hard plasticky material is not exposed to friction on the ground.
Cons:
1. while the build quality is good enough for me, I would not 100% trust it for pro usage (i.e. to be thrown around in a band wagon between gigs), as the edges and corners are definitely not heavy-duty;
2. the handle is my biggest concern, as the metal hinges seem a bit flimsy, but I have no evidence to back that up other than my visual estimation -- I'm no engineer though... I must admit however that there is no visible bending to the hinges or the handle when the case is loaded;
3. my case has the padding slightly warped in the left bottom corner of the upper lid, but I don't see it as a real problem. If it gets worse with time, I'm sure some light industrial adhesive and some good old elbow grease should fix this easily -- after all this is not Gibson money.
4. actually the only real issue I have with it (and the reason why I rated it 4/5) is that there is a lot of unusable space next to the head of the guitar. Given the shape of the guitar, the neck is aligned towards the back side of the case, so the headstock occupies roughly half the space in the leftmost compartment. This leaves a lot of space in that area (my standard Crybaby fits perfectly), BUT... I cannot actually use that space, as the Crybaby (or whatever else you would put there) would bash against the headstock once you turn the case during transport. So that huge area is only good for papers and maybe a loosely-wound cable.