I've currently got an ADSL2+ line by Snap which performs fine. It's dropped around 3-4MBPS (had a splitter originally, that died and now on new splitter and no difference to figures) over the past 6 months for some reason and is now sitting ok with the figures in the attached screengrab:

Now, looking at the line stats, would VDSL be much of an upgrade? Am I likely to get any benefit over the dsl I have now.
Cheers,
Chris