RE: What else?
More things you will eventually need?
primer pocket uniformer,neck thickness micrometer,outside neck turning tool, rcbs precision mic., dial indicator setup for measuring the runout on cases and loaded cartridges, and at this point in my life- a goodmagnifying visor. I think I "need" Quickload next.
and ditto on the powder trickler, it used to come with the rcbs kit, and a cheap plastic caliper.
Other than dies that kit had every thing I needed for 20 years, until I realized I NEEDED all this other BS.