So I've finished tryout of Centaury, and the verdict is not as good as Mypal, as it has some bugs. While it plays YouTube videos fine directly from YouTube, when you click on a YouTube link from another site (say Reddit), and go to the video....the audio is in slow-motion about half the time. Centaury seems unable to play all the video formats....some sites it plays, some never play, some videos starts and stop in spurts, and some crash it. Version 52.9.0 is not bad, but needs some work.
I have yet to upgrade Mypal 28.1.0. Still working on the bookmarks issue. The only problem I have had with this browser is that it usually freezes up if more than two 'windows' or 'tabs' are open, or if I have another browser in use. This renders everything unusable, and I have to hit the power button on the PC.
I would definitely consider upgrading to Centaury 0.0.3 and Mypal 28.3.1 (if I'm not mistaken, these are the latest versions available on feodor2's Github page at the moment). You should see even better results with fresh installations of these versions on a fresh XP SP3 install. Far and away, those are the best browsers for XP right now as far as compatibility with the modern-day Internet. If you need a browser that can handle the demands of today's World Wide Web, either Centaury or Mypal will be more than equipped for the job (it's even better if you pair them together; one picks up the other's slack extremely well!)
My current browser setup is a rather bizarre one (at least it may seem that way to some), but I'm pretty happy with it! I'm now using the latest (last?) version of Retrozilla, a fork of Gecko 1.8 (which Firefox 2.x and SeaMonkey 1.x both used) designed to improve its compatibility with present-day websites as much as is possible. The copy I have is a customized one by roytam1 which enables TLS 1.2 (giving it far greater access out of the box to modernized HTTPS sites than can be achieved with the aging Firefox 2.0.0.22pre or SeaMonkey 1.1.20pre) & restores the Firefox 2.x interface (which I have always preferred to the more intimidating interface of SeaMonkey 1.x). By this point in time, the Gecko 1.8 layout engine is definitely starting to show its age, but still gets the job done with a lot of sites (such as the 'basic view' of GMail, mobile Facebook/Twitter, and even this very forum). Retrozilla TLS1.2 is definitely the best browser you can run on Windows NT 3.51 these days, and also highly recommended for 9x users (especially those running 95 and/or 98FE). On my Core i5-4690 (3.5GHz) with 3.4GB of RAM & XP SP3 it's blazing fast, though turning off JavaScript helps tremendously in that regard. For newer sites Retrozilla TLS1.2 can't handle I've got Mypal 27.9.4 (a fork by feodor2 of the final official release in the Pale Moon 27.x.x series); while it is inferior to 28.x.x as far as site compatibility, it loads faster/uses less RAM.