I've just started an Khajiit Vampire build focusing on Illusion and Unarmed, but I'm having trouble choosing between Light or Heavy Armor. I will definitely use Daedric Gauntlets, for the Fists of Steel perk, but I don't know if they will hinder my Sneaking. If I have all Light Armor except for the Daedric Gauntlets, will my sneaking be less effective than if I wore all Light Armor?

I always wondered a similar question. If you partially use heay and partially use light, which armour tree do you gain experience in?

Surely someone who knows for sure will come along.

What I've experienced:
There are muffled boots available at some point that allow you to move silently (as I understand) - I guess it applies to all armor types.
My full Daedric set doesn't make any audible 'sound' when I move (Ebony set did make an audible sound), but within the game NPCs might be able to hear something since it's Heavy Armor.

Both/either maybe. I wear Heavy Armor and have been reminded to remove my Leather Bracers of Lockpicking when my Light Armor skill goes up as I continue through the dungeon fighting.

I think there is a penalty for wearing heavy armour and trying to sneak in it. I assume if you wear any heavy armour its going to negatively effect your sneak skill. Until you get the heavy armour perk that allows you to sneak while wearing it that is.

And, to Ji Soo isn't it based on where you get hit at? If you get hit in the heavy armour piece you raise your heavy armour skill.

I have no idea. I assume it might be something do with the type of chest piece, but I can't confirm.

If you grab fists of steel, might as well continue on and get the perk to make heavy armor have no encumbrance or other penalties. That handles any sneaking problem from what I understand, though as others have said, there are many ways to deal with this.

I've worn a combination of both Heavy and Light, and both of them do rank up. I'm guessing that if you were wearing Heavy and Light armor in a ratio of 1:3, respectively, that the Light armor would rank up faster.

i would think that the armor type that you wear on your torso would go up the quickest.

as it is the most likely to be hit in an attack.

yep

its nto based on where ur hit because Skyrim dosent have any hit boxes, what it does is every time u gte hit the "dmg exp" is divided up by 4 or 5 if ur wearing a shield, so if ur wearing 2 piecs of LA and 2 pieces of HA the "dmg exp" is divided up equally between the 2 skills, but if u wear a 2 pieces of LA and 1 piece of HA then 3/4ths of the exp goes to LA and 1/4 goes to heavy.

I don't think you get much extra benefit (as you should) from heavy armor, even though that is what I use. Next time I'll try light and see.

I like the talents for heavy better. Half fall damage is nice, as is extra damage for punching (helps when you need to brawl someone now and then...a small issue, I know). Then the stagger-reduction is great by itself. In comparison Light Armor doesn't have as many unique benefits.

I use the Steed Stone to make my heavy armor weightless . I'm wearing the Ebony Mail , and Daedric gauntlets / helmet . My boots are muffled DB ones . I see my heavy armor skill go up all the time , never seen my light go up , so I'm guessing whichever one you're wearing the most of gets the exp .
I have noticed that wearing the muffle boots makes me practically undetectable to a certain point , so if you want to wear heavy but still sneak , then get yourself a pair .

light. Heavy makes no sense on a sneaker type char.

Don't forget that your choice in armour will also determine your choice in smithing. The branch of smithing you choose not only concerns the armour you will be able to make and improve but also the offensive side: the weapons.

I think both types of armour have their merits, but daedric swords and bows are better than their glass equivalents. Even ebony weapons are better than glass. For me this definitvely settled the question in favour of the heavy smithing side and therefore also in favour of the heavy armour.