Well I'm pleased at least that your profile has been reset to allow your line a chance to find its own level again. Every little bit helps, as the adverts say.
My own recent experience with error-rates has been interesting. As far as DLM control is concerned, it seems, at least, as if max-rate banding because of apparent instability (too many resyncs) is harder to shrug off than even quite poor performance (too many errors), as DLM seems to be able to tweak this quite well, and in fact has restored my connection to 80,000 as the error-rate has died back (or BTOR have left the joint-box
).
I'm also interested to hear what was said about the BT Vision thing. If he meant BT Vision = FTTC, and therefore more of the latter, then I can understand the connection. However, what little I know about it suggests that a) they seem just to be using some sort of bandwidth reservation technique, and b) they're not even using the ability to use the availability in VDSL of two PTM streams with differing latency requirements. Quite a crude approach really. I suppose though that the continuous streaming aspect of VOD might arguably increase FEXT disproportionately compared with the normal data stream, where higher level protocols are likely to impose flow-control.
I suggest there ought to have been some sort of Offcom deal done here - more IPTV, but only if accompanied by Vectoring. But then I probably woke up at that point.
On the modem thing, perhaps it's actually a good thing then that PCP-only installations have arrived, because then the choice of modems will become an ISP/EU debate, as long as they are SIN498 compliant.
Anyway, glad there has been some movement, and I hope that DLM & the modem will now look at whatever your real error-rates are and tweak the line parameters accordingly. You never know, it might even improve things for you. I do hope so anyway.
Something I read elsewhere may be interesting for you to monitor:
INP and Delay in the profile are the input requirements, as they are what DLM sets to say what level of interleaving/FEC is required
The resultant R, D, I and N parameters are then the values that the modem selects to try to meet these requirements
Also
The modem can choose whether to offset speed against latency. Generally, the modem can attain the same level of protection by both increasing the FEC overhead size (so decreasing speed) and decreasing the interleaving size (and decreasing delay), or vice-versa.
