@Ronski: I guess you're confident @ the 450M estimate? tbh that looks about normal - you're interleaved so that won't be helping your downstream (which looks OK), and I'm guessing you're in an area with high uptake, so cross talk has a (large) part to play. I don't know, but presumably this worsens with line length? I'm unsure whether crosstalk affects your upstream more than down, but given that the amount of sync you have to play with on upstream I'd guess we're more likely to notice it... I'm praying no-one else round here signs up to "Infinity" since I was pretty pee'd off when I went from 18 down to 9.5!
Other than that, matching a Broadcom based modem with an ECI cabinet might be something else that isn't in your favour? Just throwing out random thoughts...
As KIAB mentioned, maybe worth upgrading your router firmware for a more up to date modem blob? I've seen other people moaning about the Zyxel, but I know you're a dab hand at this kind of thing (completely unrelated, but enjoyed your posts on AVForums about your cinema room!)
@NewtronStar: you say you're 1KM, how certain are you of that? BaldEagle1 mentioned in another thread that he was 1.1KM (he even posted a JDSU screen shot) so I'm not sure why I (and you!) thought he was 1.2KM, apologies if I've added any confusion... The differences (and similarities) between your two lines are interesting!
I think, looking at the stuff on MDWS, I can build up a fairly decent picture of what an HLOG should look like depending on distance - so knowing you're 1K is useful for future comparisons! Also notice that you had G.INP and they took it away - did this really make much of a difference to your attainable? (again, this is useful for comparisons)...