The problem with Desura is that, like Ubuntu One, the server is still
proprietary, making the client pretty much useless until somebody makes a
server that works with the client.
The problem with the rest is that I don't really get the point of them. From
what it looks like, Lutris is meant to configure and run proprietary games in
the best way possible (performance-wise), and the same may go for DJL.
Honestly the best game manager is just this:
http://i.imgur.com/eIrKs.png
This is just my opinion, but game managers are useless unless you're dealing
with proprietary games (ones that usually contain DRM).
