CRs for MM creatures?

[S'mon]

In many cases, CRs for big, mean, tank like critters are situational. On one hand, they can take people apart quite rapidly in melee. On the other hand, they usually have little resistence to magic, can't fly, etc. So the CR is too low if the party engages straight up, but the fight will be easy if they fly+bombard, charm it, etc. Big vermin and elementals, Dread Girallons, etc probably fall into this category.

I don't see how some of the high end outsiders have such high CRs. They tend to come apart quickly to physical attacks from magic weapons, but don't have the right powers to pull the mage's trick of staying safe.

Solar and Planetar CRs seem too low. It almost seems like their "cast spells as X level clerics" trick didn't get taken into a account.

Creature Collection CRs are a joke, you'd do better to work them out yourself.

Monster Manual CRs are a lot closer, but it does seem like they were assigned by a bunch of different people with different ideas on how the 'system' (system? what system?) worked. Big tough uglies CRs tend to be too low unless you run a very high-magic game, mostly increasing them by +1 (ogres to CR 3, Ettins CR6) seems enough. Undead CRS seem about right. For some reason most Demon CRs are much too high (Succubus is more like CR 6-7 than 9), someone (Skip?) seems to have arbitrarily assigned them so that each demon 'type' is +1 CR to the last. Devil CRs by contrast seem spot-on.

I highly recommend U-K's system, it works very well although it doesn't cover everything, eg the CR of a high-level Warrior is clearly not Fighter-1, and assessing how many powers it takes to boost a CR is tricky. But his use of 'integrated class levels' as a basis works great, eg if a Dragon spellcasts as a Sorc-15 you start with a CR 15 and go from there.