I was curious what the consensus was on the merits of practicing on past contests as opposed to simply solving problems by rating/tag. If I had a block of time (2-3 hours) to dedicate to setting up contest-like conditions, would doing virtual contests/upsolving be a stronger use of time contrasted to grinding out problems?
Virtual contests are a very accurate simulation of the real contest. They should only be done once you've allocated a good chunk of time to sit down, focus, and take the competition. However, if you want to just solve a couple problems for practice, then virtual contest is not for you.