I used Oral-B for years but switched to Sonicare a few years back and haven't regretted it. I don't have strong feelings about one necessarily being better than the other, but I think either is a big upgrade from manual brushing.

And I know this isn't what you asked, but if I were to get a new brush now I would probably consider one from Suri. The amount of waste from toothbrushes of any kind is annoying, and I'm always trying to reduce my footprint where practical. Sorry for linking a site with a bunch of affiliate links, but apparently there are a range of different eco-friendlier electric toothbrushes and brush heads for both Oral-B and Philips (I'm not affiliated with any of these companies or this site): https://greenchoicelifestyle.com/eco-friendly-electric-toothbrushes/