Telekom used "interleave" by default, which provided very slightly faster download speeds. And caused about 70 ms latency to the first hop.
I had to contact them and ask them to change my ADSL to "fast path". This dropped the latency to maybe 20 ms (IIRC, my memory might fail me on this number).
I think ISDN was about 40 ms to first hop, but again, it's been a long time.