Hello Ackbach, thank you, I have been using only Vivaldi since I adopted it following your https://mathhelpboards.com/chat-room-9/firefox-quantum-22744-post102654.html#post102654 from last year. Personally, I don't find the syncing very important, but the change from version 1.15 to 2.0 indicates that it is probably a major update overall.
(In case you happen to use a Linux distribution that does not have updated packages, or does not provide Vivaldi at all, it may be possible to just download the standard .deb or .rpm from the Vivaldi site, change the version number in your local build script and upgrade without any problem. For example, adapting the version number in this
script (still for 1.15 at the time of writing) is enough to build the new Slackware package for 2.0.)