Recs.
Updated
Vivaldi is a Chromium based browser with its UI written with web technologies (HTML/JS). Vivaldi advertises itself as a "power-user browser" as it tries to bring features built-in reducing the number of extensions needed.
Vivaldi was founded by Jón S. von Tetzchner, creator of Opera browser and its CEO until before the switch to Chromium.
SpecsUpdate
Pros
Pro Custom search engines
You can add as many search engines as you like. For example you can set up one for YouTube, one for Wikipedia, or whatever you want: you need only the URL of the search and it can be used from the URL bar (by prefixing it's nickname, yt
for YouTube for example).
Pro Built-in ad and tracker blocker
Vivaldi has a built-in blocker that allows you to select between blocking just trackers or both trackers and ads. With customizable blocking list sources, good performance, and support for all the standard blocker list features you find in ad blocker extensions (with more to come), you might not need an ad blocker extension at all.
This also comes in handy on Android, where Chromium/Vivaldi doesn't support extensions.
Pro Tab behaviour can be customised
The order you toggle, open, close or clone tabs can be modified to match a workflow that best works for you. For example you can choose tabs to toggle in recent order so you can go back and forth between the last most useful tabs without needing to change their position on the tab bar.
Pro Notes
A notes panel allows to save notes from webpages and can include screenshots for reference and have tags and organized in folders to help manage them. Thumbnails are too small and Notes do not have separate page in settings, but it should, there are a lot of things to improve.
Pro Built-in page capture
Vivaldi can grab a picture of the whole webpage or part of it and saves it automatically inside a note or as a file in your disk, or in your elected directory. But I have problems with images of full windows shown on monitor (using X Window System in GNU/Linux). Here I use system XWindow screenshots.
Pro Updates via dialog box
Unlike most modern browsers (but like most browsers of yesteryear), Vivaldi gives you a dialog box when an new version comes out; it doesn't just update silently in the background. The dialog box tells you about the changes that have been made, and lets you chose when you want to update.
Cons
Con Some non-optional telemetry
According to its privacy policy, Vivaldi sends an approximate location (country or major city), randomized ID, version, cpu architecture, screen resolution (to know what screen sizes to test on) and time since last message every 24 hours (to know amount of active users).
Con No automatic silent background updates, except on macOS
Unlike most modern browsers, Vivaldi doesn't have the option to update silently in the background. It gives you a dialog box when an update comes out. The box doesn't warn you that not updating the browser could expose you to security risks, which could be pretty bad for your average joe, who doesn't know computers that well.
Con Same security vulnerabilities as Chrome
Vivaldi uses the same browser engine as Chrome, meaning it has the same security-vulnerabilities as Chrome. Chrome is a big target for hackers (being the most popular browser in the world), and a vulnerability for Chrome will likely also exist in Vivaldi.