The difference in the slope at the start is because daveesh1 must be on a cabinet that's a long way from the exchange, whereas dwilson75's cabinet must be closer to their exchange. The strength of the VDSL2 signals is deliberately restricted so that they don't interfere with ADSL signals from the exchange. Nearer the exchange, the ADSL2+ signals will be stronger and using more frequencies towards the higher end of the ADSL2+ spectrum, so the VDSL2 signals need to be restricted over a wider range of frequencies, perhaps up to the top end of ADSL2+ at 2.2 MHz. Further away from the exchange, the ADSL signals from the exchange will be weaker, but they won't be using the higher ADSL2+ frequencies. So the VDSL2 signals only need to be restricted over a narrower range of frequencies, but because the ADSL signals are weaker, the VDSL2 signals need to be reduced more sharply.
The gap in the bitloading in the middle of the third downstream band could be almost anything, but I'm not signed up for MDWS so I won't be scrutinising the rest of their graphs to guess what it might be.
