As far as I can see (-though i've only glanced so far), the only options for being a spontaneous INT-based full caster (low BAB, 9th level spells) are Sage Archetype Sorcerer & Ley Line Guardian Witch.
1: Are there any INT-Based Spontaneous Full-Casters I've missed?
2: Comparing the two archetypes I've mentioned (or others that I havn't) what are the pros and cons of each? (and what would you recommend playing?)
Edit: I completely forgot Psychics exist... So factor them alongside the other two if answering Question 2 :)
1. Psychic, as well. You can kind of lump in Arcanist due to its prepare/spont hybrid nature.
2. Sage is just generically good. It performs just like you'd expect it to. It retains one of the best spell lists in the game.
Ley Line Guardian is a nicely spell-focused Witch, but my experience has been that the spell list for the Witch is not that great. You make up for weak spell selection via Hexes, which you don't have access to until 2nd level.
Psychic is a very different animal. It can do things more subtly due to the component change, but has difficulty in closer range as you progress due to the thought component penalty on concentration checks, which will virtually always be on if you're using metamagic. Fear effects, including intimidate, shut down casting, or at least delay it while you fish for your Remove Fear potion at low levels. Once you hit mid-high levels, you are comparable to a typical Sorceror. Occasionally you give up your swift action to ignore fear/emotion effects while you do real spells, but no big deal. The spell list is a little thin in some regards, particularly due to the old soft covers that it didn't get to draw from in development, but it has a leg up in other regards. Expect to feel less useful against mindless and immune to mind-affecting enemies for the first half of your career. That all said, the Psychic is a great counter to Wizards at higher levels, able to effectively use silence against them without penalty (typically quickened due to the cast time), having lower level access to Mind Blank, and several other nifty tools that strongly disrupt the typical Wizard's preparations. You also have a couple unique spells, like Divide Mind, that are flavorful and amazing.
My Psychic just hit 19 in PFS this weekend and was our primary countermeasure in the Karzoug fight. I have a bit of experience with the class. :-)
Psychics are int based spontaneous I believe
Updated post a few mins ago seeing as I completely forgot about psychics. I'm not counting Arcanists, as (If I understand it correctly) they still have to spend an hour at the start of each day studying their book, and without their book they're going to be in trouble.
I'm curious to see what people think the strengths and weaknesses of Sage Sorcerer, LLG Witch and Psychics are though. Especially In comparison to eachother.
Thanks to Serisan for the Psychic info too :)
Arcanist almost counts? It's, like, the only Flexible caster... but you could easily play it as a Spontaneous one if you really wanted to.
The Occultist and the Psychic are also Int-based Spontaneous casters, albeit psychic, but you didn't mention definitely wanting to play Arcane...
I'm not denying that the Arcanist is the flex caster dream, but it also has fewer spell slots per day, which is typically a big draw for the spontaneous casters. A Wizard or Arcanist casts Mind Blank on himself, maybe getting Mind Blank Communal if he's feeling generous. A Psychic just casts Mind Blank on the party.
I think the Arcanist follows the general Wizard guideline re: preparation - after 8 hours, you can re-prepare, but otherwise you still have the remainder of the prior day. The spells per day refresh as normal, but your spells prepared would remain the same if you didn't prepare new ones. In that regard, you could effectively be a spontaneous caster as long as you only pulled out the spellbook when you leveled up.