Im possibly getting ready to jump to cable. Its been my experience that atleast in my situwaytion tweaking dsl has much more negitive affect than positive.
There is no "one size fits all" connections thats why you need to finetune ;)
In short tweaking dsl for me with my isp has no positive affect. I have tried them all. I wonder if cable will be the same thing.
In the speed you have, tweaking has not much impact, and if your doing it wrong it will slow down that goes for both cable and dsl.....

VanBuren
