@ BlasterN: Most of those pro and cons are about the actual bsp filetype, which is questionable. But the general type of system is still a good idea for Quake like maps, I think.
The Worldcraft2orge tool is a really nice thing to have (thanks for coding it), but as with GTK-radiant there will be licencing issues if I am not completly mistaken. Also a editor with source available would be much nicer for comatibility and adding features.
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@ maxxoros:
I tried using Gmax and tempest for mapping when it came out back in the Quake3 days, and while it certainly is a nice tool for mapping (it is actually quite similar to gtk radiant in many ways), it lacks updates and is intentionally crippeled

Again it also isn't open-source, so it can not be modified to work great with Ogre (only by 'coding around' it) and there are also licencing issues if I remember the enduser licence of Gmax right.
Last but not least, there is a reason why the mapping community for Quake3 never really used Gmax+tempest and worked with GTK-Radiant even though gmax was getting a lot of PR and support back then
