I looked at your Textures and noticed a couple of things that you could look at to give you better results.
1: For now, until you better understand the UE4 PBR workflow try and stay away from packing your Textures maps into the various channels of your RGB Textures. Now, what you are doing is correct and I am not trying to steer you away from doing it, I just feel like trying to do this now is causing you more problems than it is worth.
2: In your Roughness, Metallic and AO map Texture, the red channel has no data inside of it. I am also not sure which channels contains which map. When I use RGB Textures like Mask, I usually use a naming scheme so people can quickly identify what goes were so, Red is always Roughness, Green is Metallic and Blue is AO. Or something like that, the key thing to take away from this is to make sure you pick something and stick with it.
3: Try adding a LERP to your Roughness input and then control the amount of Roughness by setting scalar values. This way you can get most of the work done in Substance and then tweak inside UE4. No matter what software packages say, you are always going to have to do a bit of tweaking inside of the engine to get the values to look correct. This has always been the case for me no matter what engine I use.
4: I am not sure what scale you are using, but the model that you provide was minuscule when imported into UE4. Remember that UE4 uses CM as it;s default unit and you need to make sure you use the same as well.
5: With a little tweaking of the shader I was able to get your object looking correct when viewed in the UE4 level viewport. Here is a link so you can see what I did to the Material to get it to look like it does in the image.
https://dl.dropboxusercontent.com/u/68719/Shader_Setup_00.png
6: Make sure you have a sphere reflection capture actor placed in your level or you are not going to see any reflections on your objects.
Please let me know if this helps or if you have any more questions.
Cheers-
Sam Deiter