Harder maps :P

[Aigle]

Should probably consider the hardware people play on as well. Too many objects on the map can cause lag, which would be unpleasant for those among us with weaker computers.

Also, judging by that video, it seems like that map wouldn't be much fun to play when the majority of the time your character is obscured by leaves. Also, the disadvantages for archers would be even greater on this map than any map at night. Harder maps sound like a good idea, but the implementation of something like this might be too much.

This is the Winter map (snowball fight), to be honest, I'm not lagging at all whereas on some other maps as Lake town, it's quite laggy for me and is at somepoint quite unpleasant. Even so, trees aren't so heavy on maps, it is more buldings.
As you said it isn't possible to fight too many bots with plenty of leaves on your screen. But there have to be little open space for example plains in order to get other classes usefull. 
Finally, this kind of map wouldn't be playable on hard.


By the way, open maps aren't so bad. Last days, some of the servers had a map error which meant there were open maps and people didn't hate it, of course it wasn't full server so it is just a minority.