i analysed some data of the zyxel vs the hg612 in regards to errors. Here is my view.
I think the higher crc error count isnt to do with the higher sync speed, but rather to do with the less aggressive bitswapping.
I have a reasonably steady ES and CRC count for most of the day but I do have occasional high errored seconds (SES or SES candidates). On the hg612 these few seconds per day are lower error counts, but the other 80 or so ES I get per day the CRC per ES is pretty much the same possibly even better on the zyxel. Since its only a few seconds per day this happens, it isnt really service affecting but of course is it DLM affecting? since I think DLM works on ES count (MTBE) I think it isnt DLM affecting. At least for my error pattern.
Thats my thoughts so far.
Also I averaged 5-10 CRC per day on the hg612 US, so far after 36 hours I have 0 on the zyxel. It appears better when is low error conditions but worse if a temporary burst of noise as its slower to react with bitswaps, if that makes sense.
Also my attainable is moving around, I dont know if this is due to a new crosstalk source or the zyxel. Currently its about 2mbit below what I had at start of sync.