dual wielding is possibly the most effective melee attack. Dual swords are the best for a fighter class, for their speed and for the simple fact that chillrend is a [censored]-ass sword. alternate attacking hands, whilst dodging enemy attacks, it takes small amounts of health away each hit, but the speed makes up for the lack of power, alternately max out stamina -> power attack all day

That is correct yes for the simultaneous attack... and its more noticeable if you wield a dagger and a sword(as you can see the 15x/6x popping on the upper corner) and for power dual wield attacks you need high sneak skill so you can remain undetected after the first attack.

The thread is about dual wielding effectively, but I want to bring up the RP aspect of it. In any case I appreciate Blerrger19's attempt to explain how dual wielding can be a viable build. This important because this is also about how one should look at a RP-game like Skyrim, and how it is meant to be played. There's a loft of builds with potential in Skyrim. And I am not necessary talking about the best effective builds, but more of how to be true to a role-playing perspective. The classical three main groups are mage, warrior and thief. In modern gaming there is usually a combination of the three in one way or another. In Skyrim a player should be able to choose what combination he or she see fit, to a certain extent of course. Some in this thread seem to be very engaged in discussing the negative effects of one build. That's fair I suppose, but in my view a char-build is more about being creative and figure out a solution to a challenge. I personally don't concern myself with absolutely balance among the different builds. If I can play my type of Stealth-char and succeed I'm happy, and I expect to be challenged.
My char: Khajiit. Uses only Daggers, Bows and Shouts as direct weapons, Dual wielding daggers(dual wielding Scimitars and Silver swords for fun from time to time, but not necessary). Avoiding armor except braces and boots. Clothes, braces and boots enchanted with the appropriate enchantment. I.e Fortify healing rate and Fortify stamina(Enchantment-perk: Two effects) on clothes and Fortify light armor on Leather boots and scaled braces. Paralyze- or/and Damage stamina enchantment or poison on the weapon. Shouts: Elemental fury, Slow time, Frost breath, ice form. No shield, no blocking. Focuses in dodging and avoiding damage. Many attackers: Try to take out one of the time by sneak-attack w daggers/bow. In close combat: inflict as much damage as possible before retreating, power attacks and paralyze.
As some of my fellow forum-members have mentioned, a stealth char wouldn't rush into a fight with 5 forsworns, but it would be conceivable for such a char to use the bow or power-attack with great speed on one and one. The lack of armor is by no doubt a challenge for my char as my char often have been killed with a single power attack from maces/warhammers.
Although my dear Khajiit is my creation and not necessarily the most efficient build there's no question about the fact that the dual wielding power attacks and perks are some of the best offensive combinations in the game.
All builds have their cons and pros but it is important to say that power-gaming is not necessary to have an enjoyable experience in Skyrim.

Dual-wielding power attacks with the right perks are devastating. If I ever need to dish out very high damage quickly, that's how I do it. Grab my two swords that hit around 240-ish a piece and go for a power attack.

I don't do it much these days, though, because it makes fights boring. Now I use light armor instead of heavy and go for sneak attacks with a bow and Blade of Woe. Helps keep things fresh.

I don't know how else to tell you this, dual casting is absolutely cost-ineffective. You get to do damage/heal faster, but at the cost of doing less per single unit of magica. Single test? I have hundreds of hours into a single magic-only character, I have seen the results countless times. Just go get a calculator, turn on your game, take off your four 25% magica reduction enchantments if you have them, find a quiet place to cast spells, and do it for yourself. That is the whole point of science, which you seem so adamant about, that other people can do your exact experiments and find evidence that either supports or refutes the original hypothesis. I can do this all day and keep telling you that I'm getting the same numbers, nut until you do it for yourself, it's all pointless.

Also on the topic of science, anyone knows that the phrase "scientific fact" is a complete oxymoron. Science has zero facts.