First of all, we can now find a new checkbox in the video options. It's called "allow custom content". By checking this, you allow CS to use, for example, custom models, sprites, GUI's etc. Now, since most GUI's aren't made for the new Rawinput and low video quality checkboxes, they might look odd. The easiest fix is to use my GUI, which I will constantly be updating according to the new CS updates. (http://ge.tt/4X8tb5a/v/0
Remember the old CZ models? Valve finally made a really easy-to-use fix. In the new video options you get the option of using "HD models". These are just the ordinary CZ models. To use normal CS models, just uncheck this box. If you want the CZ models, check the box.
For GUI makers, I think this will help you out:
C:\Program Files (x86)\Steam\steamapps\common\Half-Life\cstrike\resource\gameui_english.txt
"GameUI_VSync" "Toggle VSync"
"GameUI_HDModels" "Enable HD models"
"GameUI_AddonsFolder" "Enable custom content"
"GameUI_LowVideoDetail" "Low-quality video"
"GameUI_RawInput" "Raw Input"
"GameUI_RawInputLabel" "Enable HQ - Low latency mouseinput"