Thanks for the information, OrsonJ. I've made a Weaver account and am doing a small test transfer of SILK from Polo to Weaver, them from Weaver to Core. Will update with results.
EDIT: am also getting up to 16% CPU usage on my 8-core i7, Win x64.
EDIT 2: Poloniex shows a complete withdrawal, including a txid. Waiting a bit for it, but not looking promising... Can't find an old block explorer to check up on it anyways.