Okay, I wanted to do more testing to see whether the full AD pages work better compared to Arpen. Here's my results:
- Since each point of ArPen increases your AD damage by 1%, I found that for champions that have high base AD or AD champions that barely scale with AD, ArPen is better. This should be obvious.
- However, ArPen is also better for if you don't have a full page of AD runes because the ArPen primary runes give more real damage than just a small number of AD runes. For example, on Xin Zhao, when he reaches level 4 with 68 base AD... ArPen quints (10% bonus damage) outdamage AD quints (6.8 AD). Essentially, this means that ArPen quints have a crossover level of 4 (for Xin Zhao) compared to AD quints which make them the far superior option.
- In practice, this means that for champions that can't have super specialized runepages with just one. single. stat. ArPen will almost always be the superior choice. This means barely any junglers would want AD runes since they need armour etc.
- The counterpoint is that any champion that has shitty base AD but scales very well with AD will heavily benefit from AD runes. This again, should be obvious. Examples would be Ashe, Yorick, Tryndamere etc. Generally speaking, these are champions that have a crappy early game but need lots of farm.
- Also, for some reason, a whole full runepage of AD runes is waaaaaaay better than a whole full runepage of ArPen runes. This is partly because most enemies only have >30 Armour at level 1 - 6. It's also partly because the non-primary AD runes give better stats than the non-primary ArPen runes.
- This means that for champions that can easily just have one single stat in their runepages, they heavily benefit from this super specialization. Again, this mostly means Ranged AD carries because they're in barely any danger in the early game.
- It's also better for champions that scale with AD but do magic damage with those AD scaling skills. E.g: Lee Sin Tempest.
That's my results.