Filesize has nothing to do with speed most of the time ... Try the PDF Reference document [1], it's pretty fast.
The project is very active: in the three month that we investigated it, many of the pdfs that were unusable (e.g. NASAs budget report, one of the worst written PDFs I have seen so far) when we started are now fast enough. Also almost all the effort that Opera puts into the project is about performance.
I suggest you check the file again in PDF.js and report the PDF so somebody can look at it.
I used the latest version from git and also stable releases. It would take about 3min to render (for this 11MB file only, all other pdfs, albeit smaller, load fast). It was the only PDF that was slow, all others were loaded almost instantly, however the other files were much slower too.
The project is very active: in the three month that we investigated it, many of the pdfs that were unusable (e.g. NASAs budget report, one of the worst written PDFs I have seen so far) when we started are now fast enough. Also almost all the effort that Opera puts into the project is about performance.
I suggest you check the file again in PDF.js and report the PDF so somebody can look at it.
[1] http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdf...