Warning: Wall of text incoming.
I'm actually somewhat surprised that general sentiment is that the wizard is much better than the sorcerer. IMHO it's the other way around - the sorcerer is a much better caster than the wizard.
Let's compare a specialist wizard that starts at level 1 with 18 Int / 10 Cha and ends at level 20 with 24 Int / 16 Cha, with an arcane sorcerer that starts with 10 Int / 18 Cha and ends with 16 Int / 24 Cha:
- Skills: Wizard has 1 more trained skill, but sorcerer has many more signature skills. The poor wizard doesn't even have enough signature skills to get 3 legendary skills at level 20, unless you count Lore. Advantage: sorcerer.
- Resonance: Sorcerer has 4 more resonance points. Advantage: sorcerer.
- Number of feats: Wizard has 2 more class feats, but sorcerers get bloodline powers for free. It's kind of like sorcerers are forced to spend their 6th and 10th level feats on bloodline powers. I could see this going either way (the imperial bloodline powers are pretty good, for example), but the flexibility of wizards probably wins out. Advantage: wizard.
- Number of spells: Wizard gets one extra highest level spell from Drain Arcane Focus. This is especially powerful at level 1~2 (with only 1st level spells) and level 20 (with an extra 10th level spell), and at those levels the wizard is clearly more powerful than the sorcerer. Advantage: wizard. Note this advantage does not exist for universalists.
- Prepared vs spontaneous casting: Ah, the age old debate. This probably depends on playstyle, but for me personally I think spontaneous is very much superior in 2e.
In 1e, the wizard might be able to prepare 6 different spells per level in their slots, while a sorcerer may know 4 different spells per level. Not so in 2e; the wizard can prepare 4 different spells per level, while the sorcerer still knows 4 spells per level. With spontaneous heightening, the sorcerer actually has more options at any given moment than the wizard. This isn't even taking into consideration that the wizard has fewer options as the adventuring day goes on (more spells cast), while the sorcerer doesn't. Prepared casting is very much less flexible than spontaneous casting in unanticipated circumstances.
In anticipated circumstances, prepared casting is a lot more flexible, of course (and see Quick Preparation later). But here the wizard is instead limited by the vastly increased cost of learning spells. Learning a highest level spell typically costs about 20% of a character's liquid wealth from an adventuring level, before spell access costs and reduced/increased costs from critical success/failure are taken into account. So by spending 40% of their liquid wealth, a wizard might know 4~8 spells of their highest level. Gone are the days where a wizard had enough money to fill multiple spellbooks. Certainly the repertoire of spells a wizard can choose from isn't nearly as large as before.
Oh, have I mentioned that it's pretty difficult to learn high level spells now?
I think spontaneous spellcasting is vastly superior, but again it depends on playstyle.
- Wealth: Sorcerer doesn't spend 40% of liquid wealth just looking for spells, and may actually have downtime to do other stuff. Advantage: sorcerer.
Also, I'm guessing with access costs, learning a spell costs roughly as much as buying a scroll. A sorcerer can therefore take their extra wealth and load up on scrolls. Might as well use their extra resonance on something!
- Heightened mechanics: Wizards essentially know heightened versions of a spell for free, which is a pretty big deal because spells are expensive to learn. Heightened spells really helps with their spell lists. Then again, without playing at high levels I don't know how often you'd want to prepare heightened spells.
I'd argue spontaneous heighten for sorcerers is even better, though. It also gives them more extra spells known for free, and has a pretty good combo going on with Dispel Magic. I'd say advantage goes to sorcerer on this one.
- Uncommon/rare spells: It seems like wizards have an advantage on this (higher Int, and don't have to wait until leveling / retraining to learn), but imperial sorcerers get the uncommon spell Teleport. I'd say Advantage: imperial sorcerer, otherwise Advantage: wizard.
Now to the feats:
- Counterspell: Vastly better for the sorcerer than the wizard. The wizard can counter fewer spells as the adventuring day goes on, while the sorcerer can still counter just as many spells. Pair with Reflect spell for greater effect.
- Dangerous sorcery: Name aside, I don't understand why wizards don't get this feat.
- Arcane Evolution: Gives the sorcerer quite a bit of utility of prepared spellcasting.
- Empowering Focus: 1/day nova for the wizard, save it for the boss.
- Quick Preparation: This incredible feat would be the reason a pure caster may choose to play a wizard. It really depends on the GM and the party though. If the party usually goes into a dungeon with few buffs and the enemies tend to wait in their rooms until aggro'd, this feat is amazing. If the party usually has a bunch of buffs that last fewer than 10 minutes and the GM gives the enemy some organizational abilities, this feat is much less useful.
- Swift dispel: Easy way to cast Dispel Magic with just one action for the sorcerer. Why is Dispel Magic so good for the sorcerer?
- Overwhelming Spell / Overwhelming Energy: 8th level feat for sorcerers, 12th level feat for wizards.
Finally, sorcerers have better weapon proficiency for some reason.
In conclusion, for a pure caster I think the sorcerer is way better, given how much prepared spellcasting seems to have been nerfed. I may play a wizard if I wanted to multiclass, since they are more flexible with feats; or if my group is such that Quick Preparation is super exploitable. Otherwise I'd stick with the sorcerer.
