This pdf is 4 pages long, 1 page front cover, 1 page SRD, leaving 2 pages of content, providing a total of 32 new arcane discoveries for wizards to choose from, so let's check this out!
Much like the Class Acts-pdf on rogue talents, this one kicks off with a rather specific discovery: Animator lets you animate more objects with more construction points. Very specific for an arcane discovery and not too powerful, but an ok option. Arcane Signet on the other hand is ridiculously lame - at 20th level, when displaying your arcane mark or carrying it around, you gain half your class-level to diplomacy and intimidate, but only against people with at least 1 rank Knowledge (Arcana) and Spellcraft. Let's re-check that - 20th level. Timestop. Meteor-swarm. Etc. - and as a capstone, we can get paltry social skill bonuses? Against a specific set of persons to boot? Come on! AT least get rid of the restriction, this is pathetic as a capstone.
Dedicated Familiar deserves special mention, since it allows your familiar to use your character level instead of your class level to determine its power - cool, elegant, simple: Two thumbs up! Ioun bound is another one of the nicer discoveries - affix ioun stones to items to get the stone's benefit and slightly increase the item's durability. Living Spellbook is another cool discovery that makes your spellbook an intelligent item - a lot of potential in that particular one.
Speaking of potential: As much as Arcane Signet sucks as a capstone, as much rocks "None dare speak his name" - every time a creature of Int 3+ speaks your name and is on the same plane, you become aware of the distance to and direction of the speaker. AWESOME! This becomes a staple of all of my archwizards, be it as discovery or (ex), (su).
Another potential capstone, permanent magic, on the other hand could break your setting: To render spells with range of "personal" permanent, you ignore 10.000 GP of costs - can you see the repercussion when allowing a lot of spells in your campaign? As a 20th level discovery, it's okay I guess, but still - not too cool.
Rather cool are the discoveries that enable you to e.g. memorize two spells of the same school in one slot, choosing the one you want when casting the spell or even commit the memorization of a spell to a familiar. Insightful preparation is a good concept, granting you a bonus depending on the school of the highest level spell you have prepared. Each time you prepare spells, you can choose anew. And boy. +4 armor bonus for conjuration. +2 natural armor bonus for transmutation. OUCH. Plus: If you e.g. have a 4th level evocation slot, you can benefit from this discovery, but as soon as you get access 5th level spells and don't know a spell of the corresponding school, you lose access to that particular bonus from the discovery, which feels plain and simple weird to me.
Voice of Reason hits a pet-peeve of mine: The discovery gives you diplomacy as a class-skill and makes it an int-based skill. That's not good design or imaginative, but rather just bad filler. Speaking of filler: Wizened grants you +2 to Wisdom. Wait. What? Aren't age-categories used to reflect such changes? Plus: A discovery for a +2 attribute bonus is rather steep in my mind. Then there also are some discoveries that enable you to learn prestidigitation, ventriloquism, comprehend languages and message-spells - okay, but again, rather bland when compared to other ones.
Editing and formatting are good, though some wordings could be slightly clearer. Layout adheres to a 2-column standard with a parchment-like background, has no artwoks and no bookmarks, but needs none of the former at this length. All right, let's get right to it: This pdf is not perfect - part of the freshman-quartet of pdfs, this bullet points-style class-act shows some rather neat promise regarding design, but, especially with this one, I feel that less would have been more: Several of the arcane discoveries herein do not feel like arcane discoveries, but rather like other concepts, perhaps for archetypes etc. or miscellaneous new rules. That being said, there are not as many ones I'd consider broken or bland as in the one on rogues and, as in all class acts, there are multiple contents herein that can be considered winners - elegant, cool designs and iconic ideas, but the disparity between the superb ones and the rather lame ones is rather evident. That being said, if you're looking for some great arcane discoveries and can live with some that should be ignored/tweaked, you should still give this a chance - the low price and good bang-for-buck ratio still make this a valid purchase. My final verdict will thus be 3 stars due to the low price, a close scrape with the 2.5, but better than that.
[3 of 5 Stars!]