Customization, Secure, Sync, Not Chrome!
Bookmarks in the bookmarks bar lacks right-click options; No mobile version (but this too will change!)
Despite the few cons, Vivaldi has proven to be the most reliable, innovative and forward thinking browser I've ever used. The development team is top notch; they actually listen to their users, and implement features based on user priority rather than their own opinion of what's important.
Trying a new browser is always a little scary, but Vivaldi eases your fears quickly. it is well worth giving it a try.