Quill 3D Should I?

I disagree with a lot here. You could argue that more levels are made in Hammer (or similar) map tools than Max, but you aren't gonna rush out and use them, cos they aren't made for Blitz. Quill works in the same way as these tools, and is made for Blitz. It really depends on what sort of map you want to make, but having tried to use Max to make levels, I don't recommend it much. It's quite difficult keeping the texture mapping under control and navigating around the inside of tight spaces.

CodeD - ignore what you saw in Quill so far, it sounds like you were in the mesh editor and not the map editor. They are very different tools. The mesh editor is fine if you have never used anything better/pricier, but the map editor is where you will the difference will shine. Don't forget you get occlusion code/export with Quill as well.

I've also tried CShop, and it does have some neat tricks, but mostly I've found it to be buggy, underpowered and has an anti-user philosophy (in my opinion).

In summary, I don't think the best map editor exists yet for Blitz, but out of all those that do I rate Quill most highly. If you can get on with Max then use that, it is a great tool, but it won't be the complete answer: issues with lightmapping, slicing-up and occlusion will haunt you.