I've been using opera for about a decade and a half. I've been an avid spokesman for using it, converting others. Opera has always been about being at the forefront of novel features. I've used the heck out of:
Tabbed browsing (since the onset)
Sessions (this is brilliant) and its associated history
Undo (whoops, didn't mean to close that tab!) - also brilliant
Single-key browsing (why is this off by default in the last releases up to 12!??!!!!)
Right-click "close all but active"
Amazing crash recovery (continue from where I left off)
Efficient memory use (seems to be dead already by Opera 12, though)
Eventually, speed dial.
And, of course, this whole time I used bookmarks.
I loved Presto for many reasons but #1 because it wasn't the browser in the cross-hairs of hackers (and wasn't a product of Google).
This new Opera is everything I could possibly hate in a browser and is simply not Opera. It's a disgrace to even call it "Opera". It should be another product name.
I'm stuck on Opera 12 / Presto until either (1) It becomes so grossly incompatible that it's useless for day-to-day work --or-- (2) The new "Opera" adds back in 90% of what made Opera great.
The only thing great really going for me is that a huge amount of sites I visit are, by nature, unlikely to adopt the latest standards and thus will remain compatible with Presto for a long time.
Plain and simple, the new Opera alienates its existing users and makes absolutely no compelling case for anyone else to switch to it. Bringing back the old features like the ones I've listed isn't a "should", it's a "must".
My questions is, does dropping Presto really require dropping all these features? If so, Opera is 5 minutes past flat-lined on a cool day. Either defibrillate Opera 12 before the brain damage sets in, or call it DOA. 'cause right now it's headed straight to hell.