Opera doesn't want to abandon the security bandwagon of the app, so selling it takes an odd angle: it offers a speed boost. The newly released Opera 64 features a tracker blocker that prevents sites from monitoring you across the internet (usually for ads or fingerprinting for behavior) and reportedly delivers around 20% faster page load times.
That's likely to vary dramatically, but if you're looking to balance confidentiality and quality at the same time, it's something to consider. If there are hiccups, you can turn the feature off completely or on a per-site basis.
The blocker is based on the EasyPrivacy Tracking Security Database, containing a number of established tracker files. It does not decide immediately which trackers are the aggressive ones.
Beyond that, we'd add some practical enhancements. An updated preview helps you to save pages as PDFs, take all-page snapshots, and crop-specific pieces. Emojis, selfies, and text can also be added. While these are unlikely to win you over to Opera on their own (Edge has had annotation for a while), they might be helpful if you like Opera's approach and find yourself regularly commenting on shared web links.