The Vivaldi team is working hard to gut the Google spyware in Chromium on every update. Because of this only security patches are in realtime, all other updates are 1-2 weeks behind. The rest remains as user choice in the settings (save browsing, Chrome Store (without Vivaldi isn't even recognized as Chromium), G DNS and little else). Therefore, Vivaldi can be seen a hard fork. No data sended to Google, nor other third party companies (excepting naturally extensions and search engines you use, they can be not so private in any browser, Mullvad also recommend to use less extensions possibles).