With errors ther's a difference in what's acceptable between non interleaved & interleaved, and error issues could crop up seperate from any indication from any hint of a problem from your snr.
The analogy I use for the 3 main types of figures to look at:
Attenuation/loop loss; It's like listening to someone or radio at the end of the garden/road, if ther'e too far away then you can't make out whats being said unless they talk slower.
SNR/SNR margin; same situation as above, but if a neighbour has started mowing the lawn, then your trying to make out whats said over the backround row of the mower.
Errors; Like reading a document with the odd spelling/punctuation error. The odd few, no problem. If there are loads then the document becomes difficult or impossible to read
CRC errors are the most critical, closely followed by HEC errors, FEC & RS much less of a problem.
non interleaved 0-30 errors are typical, 60-70 hmm might watch this for a while just in case
>100 you've got a problem, solutions are similar in trying to cure snr issues.
interleaved crc & hec errors up to 9000-11000 ok. rs errors 15000-16000 are ok
Those are basied on running a test between 1-5min's, and on a either a BTw woosh test or a BT Openreach engineers APtS test.
I'm not very sure how all the different routers exactly compair to the way the bt tests run ie are they displaying a cumilative figure or snap shot figure over short time periods