On a 1680x1050 monitor I can't put my mouse right to the top of the screen and click the tabs. I have to go slightly lower, its the same if you don't have a window maximized but it still takes up the whole screen, you can't quickly drag your mouse pointer to the top right to close it, you have to go a little lower. Slight gripe, but still.

A better way to handle/view replays that you've saved

Total number of people online

That sound that happens when you click a tab overlaps if you click lots of tabs, maybe make it less intrusive, or shorter or something, not a fan of the sound either, but that's mostly personal.

Today needs to have more things on it, with a quick tf2 like beginner set up to get new players up to speed what some buttons do, if that is the reason you changed the tab

That's it for now