I can report a fairly seamless change from 1Password to BitWarden over the past 24 hours. If you import your 1Password vault(s) you do need to be prepared to go through the entries checking (in particular) custom fields because those in BitWarden pick some odds and ends which you’ll probably wish to delete.
I was so impressed by BitWarden that, for once, I did upgrade to a “families” plan ($40 per year if paid in advance). It’s much cheaper than 1Password and BitWarden actually has some things that are better than in 1Password (for example, the ability to have a contact with emergency access).
There are a few things which are not quite so good (I suspect I can’t have a separate vault—as opposed to “collection”—for archived logins, etc., for example) but, on the whole, BitWarden works extremely well (and sometimes autofills better than 1Password). I was very impressed that when I started the “families” plan TOTP started working immediately with my old logins (so the relevant information had been imported from 1Password). (You need to have a premium subscription of some sort to be able to use the BitWarden authenticator.)
All in all, a good and encouraging experience and I’d urge others inclined to make a switch at least to investigate BitWarden.
Stephen