What does the AP Mid GP10 meta entail?

Solution 1:

I've found a cost analysis of the core build vs the others, and a little what to expect.

http://www.rtsguru.com/game/435/article/3066/Gold-Items-In-Mid-Lane-A-CostBenefit-Analysis.html

The point is that buying up some gold per 10 items is a highly situational tactic. The most important element to determine when considering these items is your personal ability to farm. In the case of being an incredibly powerful farmer (pro players) or being an incredibly bad farmer (new players, low ELO players) these items either help you snowball more or counteract your poor farming skills. If you’re decent at last hitting (say, 50%) then you’ll hit an odd middle-ground where they are still okay items, but you may be better off getting one only one Doran’s and saving up for those more impactful items. Beware this valley and the triple gold per 10 build may just become your best friend in the middle lane.

And this one also gives a nice cost analysis, but also tells you abit about which champions and what to expect : http://www.solomid.net/guides.php?g=27381

Solution 2:

After doing a lot of research I believe I've got a much better grasp on all that the mid GP10 meta entails. I'll break down each specific part in the order I mentioned them in my question, starting with build options and ending with strengths and weaknesses.

ITEM BUILDS

There are 3 main core item builds for AP carries:

• Standard: Boots of Speed, Doran's Ringx2, Sorc Boots, Deathcap
• Rod of Ages: Boots of Speed, Catalyst, Sorc Boots, Rod of Ages, Deathcap
• Will of the Ancients: Boots of Speed, Hextech, Sorc Boots, Will of the Ancients

The GP10 item build will generally look like this:

• Standard: Boots of Speed, Philosopher's Stone, Heart of Gold, Sorc Boots, Kage's Lucky Pick, Deathcap
• Rod of Ages: Boots of Speed, Philosopher's Stone, Heart of Gold, Sorc Boots, Kage's Lucky Pick, Rod of Ages
• Will of the Ancients: Boots of Speed, Philosopher's Stone, Heart of Gold, Sorc Boots, Kage's Lucky Pick, Will of the Ancients

As you can see the GP10 build focuses on getting the GP10 items first, and then working on the build's core. This allows you to get the most out of the GP10 items as early as possible.

• NOTE: I stopped at the "core" item in each specific item build because items after that are generally based on situation, person preference, and/or playstyle.
• NOTE 2: Some people will opt out of getting Kage's Lucky Pick because it actually makes you get Deathcap/RoA/WOTA a little bit slower. See: "Results" sections of http://www.solomid.net/guides.php?g=27381
• Note 3: If you intend to sell the items; Philosopher's Stone will pay for itself after 13m 20s, Heart of Gold will pay for itself after 13m 45s, and Kage's Lucky Pick will pay for itself after 12m 46s. If you do not intend to sell the items; Philosopher's Stone will pay for itself after 26m 40s, Heart of Gold will pay for itself after 27m 30s, and Kage's Lucky Pick will pay for itself after 25m 30s.

RUNE BUILDS

There seems to only be two rune builds for this, both of which are very similar.

• Build 1: Magic Pen Marks, GP10 Seals, Magic Res. Glyphs, and GP10 Quints
• Build 2: Magic Pen Marks, GP10 Seals, AP/Lvl, and GP10 Quints

Seals and Quints are sacrificed for GP10, and Blues are interchangeable between AP/Lvl and Magic Resistance (depending on lane situation).

MASTERY BUILD

A mastery build of 9/0/21 appears to be the standard for the AP Mid GP10 meta.

STRATEGIES & CHAMPIONS

There are two basic strategies, and it largely depends on your champion and playstyle.

The first strategy is a simple farm into snowball strategy. Basically just staying in lane farming like a monster until you become too strong for the enemies to really deal with. This would require a champ that excels at clearing waves, has high damage potential, and scales into late game. The reason that this works is simply because you will gain a larger amount of gold than the enemy mid champion, as long as you can keep your farm up (I'll post a Max CS per minute chart at the end of this paragraph). Suggested champions for this strategy are: Anivia, Brand, Ezreal, Galio, Heimerdinger, Karthus, Kog'maw, Lux, Mordekaiser, Nidalee, Vladimir, and Ziggs.

The second strategy is a roaming strategy. Using the overabundance of gold to allow yourself to roam and gank more freely. Suggested champions for this strategy are: Cassipeia, Fizz, Kassadin, LeBlanc, and Veigar. It shouldn't be a huge surprised that assassins and easy gankers excel in this area.

Additionally, there are a good deal of champions that can do either strategy depending on playstyle, preference, and situation. These champions are: Ahri, Annie, Gragas, Malzahar, Morgana, Orianna, Ryze, Sion, Swain, Twisted Fate, Xerath, Zilean.

WHEN, WHY, AND HOW

This was largely covered in Lyrion's answer, but I'll reiterate here and add a few links.

WHEN: You should opt for the GP10 build if:

1. You enjoy passive laning
2. Your champion of choice scales into late game
3. You don't get severely counter-picked and your lane opponent isn't destroying you.
4. Your jungler is competent or the enemy jungler shouldn't give you a hard time.

WHY & HOW: The following posts are all really good numerical breakdowns of why and how the AP Mid GP10 build works:

• http://www.rtsguru.com/game/435/article/3066/Gold-Items-In-Mid-Lane-A-CostBenefit-Analysis.html
• http://www.sk-gaming.com/content/53972-In_depth_GP10_Study_for_AP_Carries__Graphs_Tables_and_Video
• http://www.solomid.net/guides.php?g=27381
• http://www.reignofgaming.net/blogs/a-different-view/vvinrar/20495-runes-to-win-why-you-should-buy-avarice-gp10-runes

STRENGTHS AND WEAKNESSES

Here is the meat of this whole thing really.

Strengths:

1. You will be getting stronger faster than the enemy AP Mid if and only if you keep up with him/her in farm and he/she isn't also using a GP10 build.
2. You will scale into late game like a monster. You will finish your build earlier and deal significantly more damage.
3. By finishing your build earlier you'll be able to roam quicker and have a stronger presence in other lanes.
4. By having the Philosopher's Stone and Heart of Gold you will have a significant amount of sustain and early defense.
5. By having the GP10 items, even while out of lane you are still obtaining gold. Meaning you're still getting gold, even if you go to gank another lane.

Weaknesses:

1. You will be weaker early game.
2. You are forced to play passive early.
3. If you're a slow farmer, or can't keep up with the opposing mid champion then the only thing the build does is let you keep up. The whole strategy is dependent on how well you farm as a whole, and how well you farm versus the enemy champion.

SOURCES:

• http://www.solomid.net/guides.php?g=27381
• http://www.solomid.net/guides.php?g=27712
• http://www.reignofgaming.net/blogs/a-different-view/vvinrar/20495-runes-to-win-why-you-should-buy-avarice-gp10-runes
• http://www.rtsguru.com/game/435/article/3066/Gold-Items-In-Mid-Lane-A-CostBenefit-Analysis.html
• http://www.sk-gaming.com/content/53972-In_depth_GP10_Study_for_AP_Carries__Graphs_Tables_and_Video
• http://i.imgur.com/iJYgB.jpg
• http://leagueoflegends.wikia.com/wiki/Philosopher's_Stone
• http://leagueoflegends.wikia.com/wiki/Heart_of_Gold
• http://leagueoflegends.wikia.com/wiki/Kage's_Lucky_Pick