Scribed : another Document Presentation Website

Today, I used scribd.com for saving a short insturction set on stoping MS Outlook Web Access based email spam and was impressed with speed of the online presentation resource. It allows for a variety of document formats being powerpoint, word, excel, and pdf documents in a flickr like display. Unfortunately the website slideshare has rather slow download times, and I have switched to scribd for faster download times and noticeably quick uploading of files as well. Does anyone have comments to add about Scribd or Slideshare? Any thoughts?