So when the Mpen quints get buffed on Monday, will they be a better option than running ap/level glyphs?

Trading 15 flat AP for 6.54 flat MP seams like a solid trade to me.

however, 27.5 AP at 18 vs 6.12 flat mpen?

Thoughts on either of theses please.

Weren't the AP runes getting buffed as well?

nope, just Mpen

I promise you will be happier if you get cdr instead. You currently trade a blasting wand worth of AP for 12-15% cdr depending on whether you get flat or per level. Unless you play a champ that must instagib someone in one full rotation.

Most champions simply don't bother with the quints because Sorcs + MPen reds give you roughly enough penetration to remove the base 30 MR most champions have. Using MPen quints in addition, you risk overshooting those sillies who don't get any additional MR and wasting stats. Assuming you have more MR to penetrate, the MPen options were already superior and will only be more so come the next patch. ;[

Found them:

http://euw.leagueoflegends.com/board...d.php?t=647875

Assuming these changes remain the way there are, AP runes are getting buffs as well.

Flat AP are getting buffed.

Well, in the past 5 games I've looked at opposing MR values for the team and I think I only saw 1 person sit at 30 past 5m. Most even start with around 40-50.

The masses sat at 40-60 MR up until mid game, where the tanks settled around 120-150 MR with the carries still being between 50-80 MR in the late game. Some tanky DPS would hit 100.

While it hurts to overshoot mpen, most champions running minimal resistances won't be letting themselves get caught anyway.

With you being about to obtain 21 mpen from runes now, 20 from sorc, 20 from guise, going full flat mpen will make your damage very close to true damage against all opponents save for hard tanks. And even against them, you have Void Staff level.

Better than AP/level? The consensus seems yes.

What about CDR?

I'm not so sure about this.

Keep in mind, generally everyone builds armor heavier and much earlier than MR, thinking magic users' damage is lackluster in the beginning. This is the way the meta has developed. You're essentially countering this mentality by stacking mpen early, sending your damage through the roof vs. these targets.

I will give you the simple answer. Against a champion that has a flat 30 MR (which is the most common) 1 point of Magic Penetration is more valuable than 1 point of AP once you’ve hit 130 AP. The more MR they have the less effective MP is, so if they have 60 MR 1 point of AP is equal to 1 one point of MP after 160 AP. The thing to keep in mind though is MP is hard to come by – either through Runes, Sorcerer's Shoes, Haunting Gauges, Abyssal Scepter, or Void Staff – while there are many choices to how you want to get your AP. Also, the cost of AP versus MP is not the same, so with 1000 GP you might be choosing between 40 AP or 20 MP.

Ability Power Effectiveness can be calculate as Eff = AP * ((100)/(100 + MR – MP)). Note that the scaling of the ability does not factor into AP vs MP, nor does Rabadon's Deathcap raise the value of your AP by 30%, it’s just an across the board 30% increase in damage output.

Bottom line, once you go over 150 AP 1 point of MP is more valuable than 1 point of AP. If you’re not planning on breaking 150 AP (Amumu and Poppy come to mind) favor AP over MP.

R00ler, you seem to have totally forgotten that spells have base damage, which is affected by MPen but not AP.