Oli here from the team developing Memex.

thanks for speaking my mind here :)

We built Memex for that combination of use cases in mind. So right now you can already full-text search your bookmarks, and filter by time, domain and tags. Already on the mid-term roadmap we plan to enable full-html/text snapshots of visited pages, both locally and on-demand. For the latter we are potentially working with the Internet Archive.