I'd say it is quite important for the community to have good looking leaderboards, but they are quite lacking now imo. It's very basic/bland and doesn't give enough information at all. It's quite obvious when you compare it to something like the aoe2 leaderboards:
By far the most important one to add is the current rating. It is absolutely crucial to properly understand the players strenght. Most other categories are not as crucial but still very nice to have just to liven it up and give some interesting data.
The layout of the black row > grey row > black row is also a must imo. Especially if there is more information it improves readability a lot and it's so standard i'm surprised it isn't in the client. It should also be in the Coop rankings and custom games table tab. Just noticed it already exists in the live replays tab.
Currently you can see a players information by rightclicking > show user info, but left clicking does nothing. A bit weird to me but maybe i'm nitpicking.
Also speaking off the player graph:
You can see very vaguely see some indications on the faf graph but if you compare it to the aoe2 graph the constrast is lacking.
Also maybe an idea to mix the different rating graphs? Maybe it's personal preference but i feel like it looks a lot nicer. Most chess sites do it this way as well.
Also a little bug: You can drag away the information on the leaderboards without being able to get it back:
I know i was a bit blunt but i just think these would be some nice improvements.
Kisses from the big man