If you really mean ADSL2 then those may be just as good as an ADSL one. If you mean the now standard ADSL2+, then I agree those are worse than ADSL on long lines.
In the case of either ADSL2 or ADSL2+ you can of course easily restrict them to ADSL.
The fact they should train down automatically isn't really relevant as they generally seem to hold onto the highest protocol they can get any sync at all on. Which prevents them obtaining the best sync the line can handle.
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