If the average change is small, it's not a particularly challenging thing to take 5 minutes to review something. (for context, my median change, both mailed and reviewed, is under 50 LoC, though this will depend on language, e.g. Java is notably more boilerplate-y than the languages I usually use, and I do a lot of configuration changes that are 1-3 lines by nature).
Picking up a 5 minute review after you've returned from some existing context switch (a meeting, coffee, conversation, lunch, etc.) is easy enough.
As a result, around 25% of my reviews are done within an hour, and 10% within 10 minutes. I'm a slightly fast reviewer, but approximately the same applies to reviews done of my code. And that includes reviews that require interaction with peers in Europe, which obviously require much longer because they can be mailed while I'm asleep or the reverse.
Yeah if it's a change to code you're deeply familiar with, that's not much of a context switch. In that situation, working on your own stuff or reviewing someone else's code feels basically the same, unless one of you is doing something very wrong.
Picking up a 5 minute review after you've returned from some existing context switch (a meeting, coffee, conversation, lunch, etc.) is easy enough.
As a result, around 25% of my reviews are done within an hour, and 10% within 10 minutes. I'm a slightly fast reviewer, but approximately the same applies to reviews done of my code. And that includes reviews that require interaction with peers in Europe, which obviously require much longer because they can be mailed while I'm asleep or the reverse.