I'll break it down for you:
Things not found in Mods, Official Version ONLY:
- XBox controller support
- Fixed lighting
- Continuous support
- Small additions to FPI language, including light intensity and headshots
Things only found in Mods:
- Weapon Enhancements, such as Ironsights and gun lag (AirMod)
- Dual Wielding and Ammo Pooling (Ply's Mod)
- Extensive additions to FPI language, including Camera control system, advanced variable control, player control, weapon control, HUD manipulation. (Ply's Mod)
- Optimizations to the engine and small graphical enhancements (S4Mod)
My apologies for not including features from any other Mod, I've simply stated features for the Mods that are currently useable and obtainable (legally).
As stated before, both S4Mod and Ply's Mod include features from AirMod, so getting one of them will also net you AirMod.
There are a lot of things you can only find in Mods. I've simply summed it up right there. There are more in-depth descriptions of them in their official threads.
The only thing Mods cannot provide is the reliability of official versions... but we all blame that on the DLLs Lee gave us, lol.
Mods also don't support versions newer than V1.09, and they don't include the upates from V1.08 and up. They are all (currently, at time of posting) based on the V1.07 source code, so you will only get the official engine updates up to that point.
It all just depends on what you want to get out of FPSC.
If you're unable to script, I don't recommend Ply's Mod as 90% of its potential comes through the ability to script. Though if you can script, the possibilities have proven to be quite powerful.
(Wow, did I just
NOT recommend my own Mod??
)
The one and only,