I used both of them and I am sticking with 1Password. Yes, Bitwarden is cheaper than 1Password and it is open-source, but UI is much better on 1Password.
Other differences;
- Autofill is better on 1Pass
- Sharing something is much easier on 1Password
- 1Password desktop app does everything. Bitwarden requires web vault to do many tasks.
- Browser integration is better on 1Password.
- Sync is instant on 1Password. Bitwarden still has delays, especially on Android.
- 1Password has many categories. Bitwarden is limited to 4.
- 1Password UI is much better. Just a quick example. If you change something, like editing one login item, 1Password app stays where you are, but Bitwarden refreshes the screen and goes to the beginning. It is driving me crazy.
- 1Password has Apple Watch app.
Edit. 1Password is not open source, that is true. but they have bug bounty programs and frequent 3rd party audits. This makes them trustworthy in my eyes.