Maybe just advanced effects and stuff. Like waterfalls, and more weather effects. That's a good question though. What
can they add to source?
I use spirit because:
- Better for prop_models using the env_model entity, also easier to work with animations for props.
- Skyboxes.
- Can play mp3 bgm through fmod, which is already coded in.
- Better console commands (like fire +target and fire -target for switching on/off)
- trigger_command can fire console commands like exec script.cfg
- Movewith entities are fun.
- Aurora stuff is just plain cool, even though i don't use it too often
- The Glass floor effect is cheap and easy.
- Trigger_inout is great for those doors that open when you approach and close after when you walk away.
- Adjustable monster size and health amount, as well as the choice to change the skin or model within hammer without affecting every model. i.e. grunt_red.mdl and grunt_blue.mdl can share the same monster_grunt entity.
- Factions, you can make any monster friend for foe, or whatever.
As well as a plethora of other things i haven't learned to use. I'm still playing with locus stuff.
Overall, Spirit is a blessing on the mod world. Get it and try it.