Hardware rendering is a big step and probably the biggest addition to the game in it's 10 years of existence.
Achieving constant 125 FPS is no longer a dream and almost everyone will be able to enjoy both the gameplay and the look of the game.
If you have a decent graphics card, that is. I'm actually running HD WAY slower than 4.1.
I don't like this modelling stuff, mapping just loses its flair of moving brushes around.
Radiant doesn't require a modelling tool and that's what at least attracted me to it. It's very easy to pick up and work with it, of which at least the first isn't true for Blender (Can't speak for Max since that's a *little* too expensive for me).
If it's for placing props and sculpting terrain I can go use CryEngine 3 too, their editor is optimized for something like this.
I really don't care if it's more optimized/modern in the end, since mapping is a hobby I just want to have fun with it.
I have tried mapping in Blender already and it wasn't fun at all.
Oh well, finish Italy and UrT mapping is dead for me then.