After I updated from Opera 9 to opera 12 (a long time ago) I have really enjoyed the feature "Tab Stacking". It helped me keep my tabs open and ready to read. I recently started having issues with Opera 12, so I updated to the latest Opera 26. I noticed that the "Tab Stacking" feature was gone. I know we have the Special Dial but its not the same....
The Tab Stacking really helped me when I was doing my work and had to read few (more than 20/30) pages at once to get some references for my Uni reports.
I was hoping that there would be Opera extension which would allow this feature once again but nope
I really enjoyed that feature and hope they bring it back again.