At first I thought I would only use it for the smallest of stitches on congress cloth, but now I want to use it all the time. My current project is on 18 count dark blue canvas, stitching with dark blue threads, and the new magnifying glass is proving invaluable. The photo below shows how well it magnifies. You can even see the inset lens enlarging a portion of the snowflake . I'm hooked!
PS I've been warned to keep a cover over the glass when not stitching to avoid burns. Now I'm remembering grade school experiments using magnifying glasses and how quickly something can be set on fire.