jackhammer.hlfx.ru/en/
Has anyone used this editor? For those who havent heard of it, its developers say there may be some bugs/issues since its fairly new but the idea is to take the best features of many game editors and put them together in one.

My understanding is that Jackhammer is a Quake and Quake 2 engine editor. Looks very traditional, which is not a bad thing BTW.

If you are looking at Quake editors, be sure to check out TrenchBroom too: kristianduske.com/trenchbroom/