I kind of like RnL. Yeah sure on the old Normandy map you could shoot into the fog by aiming above their shadows and everything seems very pixelly. But its something new, the main thing that I like about playing source mods is the actual use of darkness. If you make an area too dark in RO then your player sort of glows (Partisan forest raid, personal experiments). On the one RnL map that takes place in a small town at night, can't remember the name obviously, it is gratifying to crawl in the shadows directly towards an enemy and know he doesn't see you.
Remark:
In the end it is just another western front war game that we are all tired of and a better use of the source engine can be found in Zombie panic! (which is also a great game to sneak around in the shadows) and Age of Chivalry