our neglect slows down firefox, not speed dial Rated 5 out of 5 stars

by default speed dial captures the whole website as a scrollable thumbnail (try scroll your middle mouse over the thumbnails). Therefore, everytime speed dial is called up, it starts loading dozens of such large image. The solution is to crop the thumbnail to a reasonable size. There are three ways of doing this: Right click on a thumbnail -> Edit ->

1/ Layout -> No scaling
2/ Crop -> Fill in the desired numbers or Open crop slector (you may also want to apply the above solution to make your thumbnail completely not scrollable)
3/ Basic -> Make image from -> Browse to a logo or something you like

This review is for a previous version of the add-on (