I like to have it both ways. Given the options available so far I've preferred to have bookmarks shared between both and mainly keep tabs / working context separate.

The best I've managed so far is to run separate instances of Firefox with the same Sync Account which appear as separate 'devices'. Nightly with a different icon and theme makes it obvious which is which.

This way if I come across something interesting I want dig into further on my own time, I can bookmark it as well as 'Send Tab To Device -> Home' or 'Phone' depending on where I want to be and what environment I want to have available when I see it later (e.g. read only, or hands on).

Yes, I may be hoarding a lot of tabs but that's a separate issue...