Personally I'm not very fond of the visual changes that were made in the Anniversary Edition, so I did some research and experimenting to make that version look more like the original game.

1. Removing the new textures and especially the normal maps:
- In "...\Spellforce 2 Anniversary Edition\addon1" rename the "gfx" folder to "gfx.bak".
- In "...\Spellforce 2 Anniversary Edition\base" create a copy of the "gfx" folder and rename it to "gfx.bak".
- Delete the content of "...\Spellforce 2 Anniversary Edition\base\gfx" except for the file "common\default_normal.tga". (Without this file you will get graphical glitches.)

2. Editing the config:
- Open the file "MyDocuments\SpellForce2\config.xml" with an editor.
- Change the value of "optionenableblur" to "0". (This disables the blurring of the background, when a menu is open.)
- Also change the values of "optionenablesharpen", "optionenablenoise" and "optionenablecolorgrading" to "0". (These are post processing effects you probably don't want, especially the sharpen effect.)
Note: It the options don't exist in you config file, you can add them after "<vismain".

Here are some screenshots for comparison:
http://www.framecompare.com/screenshotcomparison/0B91NNNU
http://www.framecompare.com/screenshotcomparison/WL7GNNNX
http://www.framecompare.com/screenshotcomparison/0B9MNNNU

Thank you for that! You did a great favor with this for the community!

For these who have compatibilty issues or questionable performence:

SpellForce 2 Hardware Patch 1.2
This Patch Updates all SpellForce 2 Games (Shadow Wars, Dragon Storm, Dragon Storm Stand Alone, Gold Edition, Hero Edition, Faith in Destiny and Demons of the Past) to work better with your current modern hardware and includes Widescreen support.
You can change the screenlanguage at any time in the upper right corner.

- Updates and registrated the currently used CPU + GPU in all SpellForce installations
- fixes most starting issues on modern systems
- Adds Widescreen config for SF2-SW, SF2-DS, SF2-Gold and SF2-Hero

Changelog (1.11 -> 1.2)
____________________

- Updated Game Search and detection Engine to handle empty drives and no longer stop hald way
- added config.xml creation to fix possible start up issues for Users of the "Anniversary Edition" on Steam and GoG

!!!please start the Patch with admin permissions or in some cases it can NOT scan the folders for the installation and detect the version files !!!

Download: https://www.moddb.com/games/spellforce2-shadow-wars/downloads/spellforce-2-hardware-patch-111

@M-u-ddy: thank you, it makes really great changes. Look much, much better now!

Thank you, M-u-ddy for this step-by-step instructions. It looks much nicer and works smoother.