1 - Suggestions on where problems have been solved before. (Your point)
2 - Having people say, "Here's the style we use to make this easier to support in the future"
3 - Mentoring on tougher problems, and turning quick hacks into elegant solutions.
4 - QA. (This is the stated benefit, but falls below the other 3)
The key is not to turn code reviews into a bottleneck. If you just view the purpose as any 1 of the 4, you're likely to under-prioritize or over-formalize it.
1 - Suggestions on where problems have been solved before. (Your point)
2 - Having people say, "Here's the style we use to make this easier to support in the future"
3 - Mentoring on tougher problems, and turning quick hacks into elegant solutions.
4 - QA. (This is the stated benefit, but falls below the other 3)
The key is not to turn code reviews into a bottleneck. If you just view the purpose as any 1 of the 4, you're likely to under-prioritize or over-formalize it.