Im not sure you realize how the armor cap works.
http://www.uesp.net/wiki/Skyrim:Armor_Rating#Armor_Rating
You can reach armor cap/near pretty easily with light armor you just save a few perks with heavy armor. Armor on light armor needed to be lower for release to justify heavy armor but unfortunately it's not justified, a melee char that uses light armor is actually in a better postion than one with heavy armor (Sprinting costs less stamina, stamina regnerates faster, less weight) etc.
You can get that same stamina amount by getting the weightless perk.... The only way you can get a light armor set to the quality of heavy armor is with exploits or abusing the potion and enchantments system. Heavy armor is arguably better, since with the weightless perk I can move just as fast, and get more protection. Depends on your style.
Heavy
Advantages:
- Heavy armor is more protective than light armor.
- You can deal more unarmed damage with the Fists of Steel perk. This can be combined with the http://www.uesp.net/wiki/Skyrim:Fortify_Unarmed_Damage enchantment to provide a viable damage-dealing means.
- More enemies may be engaged at once, providing more confidence to the player.
- Reflect Blows grants more offensive possibilities, allowing for more damage in the same amount of time.
Disadvantages:
- Heavy armor causes you to move more slowly than when wearing light armor (this may be negated by http://www.uesp.net/wiki/Skyrim:The_Steed_Stone or the Conditioning perk).
- Sprinting in heavy armor uses more stamina than sprinting in light armor or clothing (may also be nulled by http://www.uesp.net/wiki/Skyrim:The_Steed_Stone or the Conditioning perk).
- Heavy armor weighs more than light armor, which increases the chance of being detected while moving in stealth mode and leaves you unable to add as much to your inventory before your http://www.uesp.net/wiki/Skyrim:Carry_Weight is exceeded (again, negated by http://www.uesp.net/wiki/Skyrim:The_Steed_Stone or the Conditioning perk).
Light
Advantages:
- Lighter and less movement penalties.
- Less noisy and easier for sneaking.
- Unhindered perk (worn light armor is weightless) is available 20 levels earlier than Heavy Armor's Conditioning, and doesn't require taking two highly situational perks to unlock.
- Uses less stamina when sprinting.
- Stamina recovers faster with Wind Walker perk.
- Can be faster than the enemy (i.e. easier to run from a fight to recover from damage.)
- The lighter weight allows for the carrying of multiple suits of armor, each fine-tuned for specific enemies and situations, without drastically taking up encumbrance.
- Fully mastering the Light Armor tree requires two fewer perks over Heavy Armor (10 total points versus 12), allowing for more growth in other skill trees.
- Deft Movement has a small chance to negate combat damage, increasing overall defense.
- When in werewolf form, your armor is considered light armor, and is affected by some light armor perks. This also means that when in human form, you can use light armor instead of heavy armor to potentially save perks. (As of patch 1.3.10 this is no longer true.)[verification needed]
Disadvantages:
- Much less protective in the early game. However, later on, with high support skills, both armors are able to reach the http://www.uesp.net/wiki/Skyrim:Armor#Armor_Cap.
- Bare fist (unarmed) attacks are less powerful without Fists of Steel, though at present this perk only uses the base value of the armor, not the upgraded value, and this perk can be somewhat replaced with fortify unarmed. This may or may not be intentional.
- Reflect Blows can share melee damage with attackers, increasing overall offense.
Pretty much comes down to preference. But light is not better than heavy. Any disadvantages you'd have with heavy is nullified with the weightless perk.