Check out Mafia which is four years old- does pretty much everything Source does(doesn't support HDR and its' water isn't up to Source)- except it does it faster and in MUCH larger environments.
By that same reasoning check out Tenebrae that came out 2-3 years before Doom 3 and it does everything Doom 3 does (stencil volume shadows, per pixel lighting, normal mapping) but it also has full support for liquids including shaders, particles and transparency.
And I'm sorry, I've just a checked a bunch of Mafia screenshots and they look absolutely primitive and cartoonish compared to what even the initial build of Source could do, especially the outdoor areas. Soldier of Fortune is also a 2002 game and even its outdoor scenes are vastly superior to Mafia's.
Now when you add Lost Coast to the mix there is simply no comparison. Vampire Bloodlines runs an ancient build of Source and even its visuals are still amazing, especially the facial animation system that is capable of rendering recognizable emotions on characters and other things like moving eyeballs and blinking eyelids.
Last I was aware 8x AA modes did not function under OpenGL with any singular graphics card- I do not know the state of how they work is what I was talking about.
It's quite simple - the driver forces it just like it's been forcing other AA and AF modes for years. And 8xAA/16xAA most certainly work in OpenGL games unless I'm somehow imagining the IQ gain and performance drop over 4xAA.
If it is an unsupported mode you could be hanging up on a driver issue and not on the game engine.
nVidia has offered 8xAA right from their driver control panel for years. There's nothing unsupported about it.
but ask yourself what would make a game fall down like that after you are alreadying running it some twenty times higher then it ever was supposed to support and it was doing so without issue?
It's a bottleneck in the game code. This is trivially verified by benchmarking the GLQuake derivatives that run faster and offer better image quality at the same time, especially with respect to the animation system.
I can barely break 100FPS in Unreal to date
Unreal is definitely more CPU limited than GLQuake, no doubts there. However scaling goes both ways and at high detail levels even Unreal scales better than GLQuake does.
D3 can do everything Source is doing- already
Really? So tell me, where exactly is Doom 3 rendering liquids and HDR? Additionally I haven't seen any of Doom 3's characters render the same kinds of facial expressions that Vampire Bloodlines can do despite running on an ancient build of Source.
Doom 3 is a great engine for what it can do, no doubts there. But for overall scaling and flexibility I firmly believe Source is better. It has a better IQ/performance ratio, very fast and good-looking HDR (probably the best implementation out there in terms of performance/IQ ratio), a great mix of indoor and outdoor technologies, an outstanding facial animation system and even old hardware can get excellent visuals.