That being said, the ONE feature I want from a "better bookmark manager" is some sort of natural language processing feature. I want the manager to scan the page in question, add the relevant tags, and categorize it AUTOMATICALLY. This is the one killer feature that would actually get me to pay real money to support the product.
All of these alternate bookmark managers seem to only be unique in the UI, not in the backend. Syncing across multiple-browsers is commonplace, and nowadays a given. Give me something to really make my life easier, such as automatic categorization.
I want this because I have upwards of 200-500 bookmarks at any given moment that are not categorized. The all sit in one giant list. I like to hit Ctrl-D and save. Later, when I get the time, usually on weekends, I'll try to go through the list and categorize and add tags. I like the way Chrome and Firefox's interface for bookmarks work, I don't want to change them. I would like however an end to the tedium of actually figuring out where a particular URL sits in my mind-map.