UI in Vivaldi is unique, you can set it to simple as an old IE or to an dashboard of an Spaceshuttle and everything in between in the settings and more with CSS. Also using of more than 4000 themes, or made and share your own. You can install Chrome extensions, but most are redundant because of the own inbuild ones, or even install directly userscripts as extensions.
UI in Vivaldi is unique, you can set it to simple as an old IE or to an dashboard of an Spaceshuttle and everything in between in the settings and more with CSS. Also using of more than 4000 themes, or made and share your own. You can install Chrome extensions, but most are redundant because of the own inbuild ones, or even install directly userscripts as extensions.