http://terminus.i2p/r/main/93/258/2
It lacks proper table objects and dynamic arrays, pivot tables are pure clunk and not performant, the macro scripting is a deficient bolt-on compared to VBA, there's nothing really analogous to Power Query and Power Pivot, and it seems a little too easy to run into bugs that just crash the program. Importing CSVs is still superior in Calc, but Excel has mostly caught up.