Dwarves clean not only underground caves and caverns. Even your tavern and depot on surface gets cleaned too. They need just have some reason to idle for a wee close to dirt patch.
Lots of less bugs in Dwarf Fortress. FPS was improved by 75%. Very playable experience now. [Warning: does not apply to Adventure Mode]
Emotional system causes issue with rain, rotting cloths and seeing dead bodies. So from start assume, you will need to put some immigrants, and maybe few of the starting 7 dwarves under bridge for smashing, or to expel them out with new banish feature. This option is accessible in same place there you enable jobs on dwarves in vanilla DF.
New map for world, which was missing in Fortress Mode. Not much to do there, but to send raids. Because squads are returning 1 dwarf by 1 dwarf and it can erase those arriving with animals or invasions or caravans... so you better send 1-2 squads max on raids and not at beginning or ending of the month. Other options do not do much.
Some inter-workings involving temples, taverns and libraries were improved, but creating first books in libraries seems a wee bugy (if not extremely prolonged) for some reason.
No new buildings/workshops to play with, but lots of bugs cleared and fps death comes much later now