Bug: Overly Sharp Highlights in PBR
Just to comment on the 0.16*Specular^2 term that was mentioned in the comments by Karim:

Frostbite only remaps the specularity for their internal purpose so that they can pack gemstones specularity into the 8bit channel. They just lose some precision in favor of more variation. The specularity value is the original one when rendering.

Check the Disney BRDF viewer which is a awesome start for PBR, since it contains the whole BRDF from Disney.
BRDF Explorer | Walt Disney Animation Studios

Also, if you are looking at a better Fresnel function than

vec3 Light_F(in vec3 Specular, in float VH) {
    // Fresnel Schlick
    return Specular + (1-Specular) * pow(1-VH, 5.0f);
}


Use this instead since it takes roughness/gloss into account:

vec3 Light_F(in vec3 Specular, in float VH, in float gloss) 
{
    return Specular + (max(vec3(gloss), Specular) - Specular) * pow(1-VH, 5.0f);
}