the bug is in the shadows side of things

Low altitude stutters are also result of sound. I had stuttering land at <100m in MP. Turned off Voices (Speech or whatever it is labeled in English version) in sound options and stutters went away. AI talks was probably taking too much resources and interrupted texture loading.

The sound definitely causes some stutters for me

Luckily a new sound engine is in the works. Hopefully that would ease a part of the stutters.

Lowering texture quality is what i've been telling people that had problems getting steady FPS to try all along.

The amount of VRAM used by the sim as tested by other users and the way some textures loaded incrementally (first the low detail LODs, then the medium ones and then the high ones) in the initial versions of CoD, causing glitches similar to those i've seen on FSX on a friend's PC when he would set his graphics too high, convinced me that there's just not enough VRAM to load everything and it has to be swapped in and out of VRAM.

So, when we got the ability to use reduced resolution textures in one of the patches it was the first thing i did and the sim has been perfectly playable ever since on my two year old hardware.

As for looking ugly, the only issue is that some of the stencils on aircraft and cockpits have text that's a bit blurry some times. The landscape is looking good enough and to be honest, i've found out that setting textures to medium and land shading to high looks better and runs faster than doing it the opposite way (original size textures and setting land shading to low).

In any case, glad it's working out for you guys ;)

In my case, the stuttering was a direct case of my 1gb card just not having enough vram on 'high' texture detail. Lowering the setting to 'medium' made all the difference in the world and I enjoy a virtually completely stutter-free experience now.
I'm a bit surprised some (a lot?) of people still haven't really figured out the link between the texture detail and video card vram.
The choice is a simple one: buy a card with more vram or lower the texture detail.

Has anyone tried the high-res texture patch for Crysis 2? It requires about 1.5 to 2gb of vram, and stuttering is present in that game at the 'extreme' setting as well, for guys with cards with less than the reccommended vram.

To say the true, today game devs are a little bit "lazy" in terms of optimization of textures... With today cards that have +3GB of VRAM, I'm afraid that this behaviour will lead to even less work in optimization of textures... The problem isn't the detail of the texture, is the size. We can have detailed textures if devs go back in time and do the texture work like was some time ago, using small textures like "bricks" in a wall for some big part...

What about texture compression algorithm? Isn't DX11 supposed to have this and do it better? Hopefully they have this switch built in somewhere.

does ssd drives and a lot of memory help with such issues?

I suppose that is true. Devs have been spoilt a bit. ;)
Most video cards ship with 1gb of vram or more these days though, so unless people are running some pretty old hardware, they should at least be able to run texture detail on medium settings.