Measure the initial load time, subsequent loads are indeed faster
And to test many replies you actually have to see them since they're not loaded on page load, only when you get to the bottom of that page, so just opening the top doesn't test anything re. lots of replies
And to test many replies you actually have to see them since they're not loaded on page load, only when you get to the bottom of that page, so just opening the top doesn't test anything re. lots of replies