Most notable features:

• The program does not keep being in memory on exit like Jed's Model Viewer.
• Supports models with 20,000 polys in each submodel.
• Functionality is almost like in Jed's MV. (Except playing event sounds)
• Automatic detection of view models. (View models already opened in first person camera, you can change camera view with V hotkey)
• Proposes to save the model after making changes to it on exit.
• Able to manipulate blending in animations.
• Support of new texture flags, including Paranoia 2 ones.
• Takes up little space on computer. (contains one .exe file only)
• Supports lefthanded view-models for CS
• Able to change top and bottom colors of DM_Base and Remap Textures (Added in 1.28 beta)
• Has build in editor to configure model origin, attachments, hitboxes, eye position, bound and clip boxes. (Added in 1.28 beta)
• Editor has two modes, QC Source, and Real Model.
• Visual preview of muzzle-flashes. (When animation have appropriate events)
• And many other changes

Here is an official link for the editor, the author uploads newest versions here: Hlfx.ru

Also if you found some bugs or want suggest features, you better register on that forum and tell to author itself, I just uploaded it here and have nothing to do with the program.

Click to download hlmv_v28beta.zip if it doesn't start automatically or try another mirror.