No, but my replacement 830 has just turned up.

The relocation event ties in exactly with an increase in write speed. The relocation occured during idle time following the Windoze update. I thought the increase was due to the idle time, but the drive has still maintained faster speeds a day later. I therfore suspect that both read and write speeds will be impacted before the sectors get relocated, and I would guess that this is exactly what caused Christopher’s drive to slow down.