It's a neat feature though in other respects Opera has been all over the place since being bought by the controversial Chinese company Qihoo 360.
Recently they silently implemented their own
ads injected into websites, ventures with predatory
short term loans in underprivileged areas, apart from the feature missing from prior to their browser engine change.
Personally I'm fond of Vivaldi now, made by the original Opera co-founder, though also use FF.