I have the Magnet triple package in the Limerick area (Castletroy) and I upgraded to 8MB download (previously 2MB). I noticed no difference after a number of calls to the customer support.
I was getting increasinly frustrated until my brother tried out his new PC on my modem and hey presto!, lightning fast speeds (>10MB). Turned out my PC was the problem, just like Magnet's tech support had suggested (I didn't believe them!). Turns out it was an obscure set of settings in Windows XP.
I sorted this out myself by downloading TCP Optimizer at
SpeedGuide.net :: TCP Optimizer / Downloads and increasing the expected download speed.
Hope this is out use to someone else out there who is as hopping mad as I was!