By no means a record time solver, but ...
Reading speed varies for different people. I read more than twice as fast as my daughter, with much higher comprehension. (For reference, I can read a typical 350 page paperback in about three hours.) This gives me an edge reading clues. I can skim a clue and quickly know if it is saying A is B, A is not B, A is more or less than B, and so on. If I'm not spending time marking boxes, I can read the clues of a 4x5 puzzle in about 30 seconds. If I'm marking boxes, it can take one to two minutes depending on the puzzle.
Beyond that, I find my speed varies a lot from puzzle to puzzle dependent on several things. Puzzles with lots of numbers are harder than words. One with the number of friends on each of thee social media is the worst. Earthquakes with years and minutes and strength is also a challenge. Irregular number gaps also throw me off. One of my least favorite is times that are half an hour apart, then one clue will say 150 minutes. Another is finishing one puzzle with things a dollar apart and the next puzzle they're two minutes apart. The sequence of clues and how many of certain types can make a lot of difference. Some puzzles feel way harder to find the connections than others.