I would love to see some more statistics at the statistics screen. I like to see the stats after the game, but i feel some things are missing.
At voobly this is visible at the profile page. It just shows in which minute you do which resources. It is great to compare this time line with the game itself to spot your issues for example.
After the game we also see some time line of the population. This only shows the number of vills and number of military. What i for example what to see is that you can filter on vills only and it just shows all kind of vills (Farmers, hunters, lumberjacks, gold miners, stone miners, idles, …). This is an easy way to look back at the game and see if you had few idles and if your distribution about all resources was good. This will help people to improve.
I also like the same for military. Dont just shows us a graph of just military, but break in down to infantry, archers, cavs, siege, monks and UU. Have some timeline that just show these numbers over time. That makes it much more easy to spot when you was lacking military and what military the enemy had. This also makes it much more easy to analyse your games and thus improve.
I also would like to see graphs about current statistics on a time line. Now you can only see the number of kills / deaths at the end of the game. It would be nice if it was a graph which showed you when you get kills and losses. I also would love to see graphs about the number of resources of each kind over time.
These ideas can be even expanded futher. I would love to see an increase in the available stats.
Note: For players stats are only visible after the game, but for spectators /replay the need to be available during the game too.