I have to disagree there banes. I love rene51 and find it to be a good 1v1 / 2v2 map. I guess it comes down to playstyle and favorite weapon. There are for instance not that many narrow spots where floor/wall-damage from Rocket Launcher would matter. Map is open and circular so its easy to get good speed around the whole map.
I think I'd have to agree with Banes and Element here....The map seems way too open to me.