i remember when someone went house on gtk a while back, and with good reason. even tho it wasn't brought to light in the best of manners... the dude slammed the gtk team pretty roughly... he brought to light some valid points that all designers who worked with it already knew.
The gtk team adds tons of functionality with each build, but removes just the same amount with each build with no reason other then they try to determine how the interface should be used and disregard those that have been using it and have been accustomed to it for years.
The best build ever imo is the 1.1-ta-beta build. I have the source for it, and compiled what I could into 1.1.3. Several dozen things were changed from 1.1.beta into 1.1.3, so I just basically built my own; it wasn't hard to do. Most notably was the blue widget size scaling that is all familiar with q3radiant and now doom3radiant, where the blue camera icon is the scale of the player.
The biggest thing that changed, however, was when I got 1.2.1 and wondered what happened to my ability to change the class of any entity by simply right clicking the selected ent and picking from the menu.
I placed a bug report and was immediately told that I was 'doing it wrong for all this time'. After some time of explaining that this was in the manual that's distributed with the current version, and was even a requested feature in q3r 201 and put in by one of the ID team (I really had to dig for that years-old-log on the web), I got livid at the self-proclaimed godhead attitude that I started to experience from the developers. Eventually after enough whining and bitching ttimo placaded me and shoved the bug into the 1.3 milestone.
The gtk developers do not map like the community maps. They try to extend their powers over the mapping community. It is not for the community, by the community that the logo should say, but rather for the developers, by the developers.
The gtk interface is bunk but then again any gtk interface is bunk, thats the nature of cygwin on win32's. Its slower then q3r, its more buggy, and it uses a crapload of more memory then it's predicessors. What it DOES have, however, is allot of nifty features that are very useful, noteably the plugins, model scaling, and brush placement fixes that keep 'ghost' brushes from appearing.
But the entity placement and changing class aspect will make me shout at it and state it's similarity to the pilings on the outskirts of the neighborhood lawns left by household pets. Anything that slows me down during heavy development is a BadThing, especially because of the whim of a developer who said 'I was doing it wrong all this time' and decided to try to prove his coding ability and touched the one useful and integral part of the editor I really needed.