I am considering upgrading to 4 Mb to 12 MB, but would like to know what the effect would be, not so much for streaming media and file downloads. But more for
A) Interaction with sites with heavy reloads (like http://drupal.org/project/Modules
B) Skype video and similar
1) In general, what would be the difference between the two speeds?
2) How can I find out if my provider is the bottleneck.
(For 2 the best I can think of is to find out my maximum bandwidth on my PC, find out if it corresponds to the official limit, and then see how close i get with the tasks in question)