AshuraDX

I really hate making hills in Radiant, so usually I use outside programs for that. Making something in 3dsMax is also possible, you simply add them as md3 into the map, and make them solid (via solid brushes or preferences).

You can only do so much without having to touch radiant. In the end, you need to know how to use radiant, whether your level is 90% models or all brushwork.

I sorta like it but I guess it can be time consuming