I was a long time user of Opera up to version 12. I used the superb bookmarking as a reference library with 2000+ bookmarks in multiple nested folders. When they borked the feature I moved to Firefox as you can make it do pretty much the same thing with a couple of add-ons then last year FF started to get a bit flaky with some sites and a bit slow which ain't so good when your life involves booking planes a couple of hours ahead. Misbehaving browsers I just don't need.
So I moved to Chrome - rock solid browsing and kind of awkward bookmarking but it works kind of OK. I'm hoping someone will write a decent cloud shareable bookmark app so we can all use whatever browser we damn well want but it doesn't seem forthcoming and I keep checking back on Opera hoping they'll wake up sometime and listen to the actual users but that doesn't seem too likely either.
One thing I am keeping an eye on though is Otter. They're promising to make an Opera 12 clone with a new engine and yes... a proper bookmarking panel. So maybe you guys might like to check this out:
Cheers
Jeff