I was actually thinking it may be crosstalk related as I was referring to Sync speeds (unlocked HG612) rather than throughput speeds affected by network contention (although they have obviously also lowered as sync speeds have lowered).
I still usually see throughput speeds at around 97% of IP Profile which is around 96.79% of sync speed - at all times of the day, which suggests I'm not experiencing network contention issues, but my QLN graph does show a "noisier" connection than it used to be.
Edited by deleted (Sat 13-Oct-12 20:14:55)