Dragon Compendium is, IIRC, considered to be a 'real' book, rather than part of the magazine.
As for the template, well, the con penalty hurts, and if you don't have a charisma bonus the supernatural abilities aren't useful at all. At low levels you're far more susceptibility to melee damage (extra d6 damage from any iron or steel = ow!) Later on your DR will apply to it (explicitly mentioned), but at low levels you're ridiculously squishy. Since I'd imagine that cold iron weapons count as iron or steel, the weapons that can hurt you will hurt you more, so...
Having the fey type is a bit of a tossup, but for many characters it's a disadvantage.
The most powerful season ability, winter's chill, can't be turned off, so if you have any living nonfey in your party, don't expect them to stand next to you.
And the wings/eyes are, practically speaking, going to be decided on by the DM. And the decision will be "no".
So it's unbalanced, but not quite as bad as it looks. One alteration that makes it more palatable is the DR being changed back from "cold iron" to "iron or steel", which reduces its usefulness considerably. Winter's Chill should be capped at half your level, and the vision/wing upgrades are rolled into some sorta savage progression.