I assume I would use the same password to access those clients?
Yes, your credentials are the same on all clients as they are stored in the blockchain.
Are there any comparisons (preferably a chart) between the different UIs?
Not to my knowledge. Might be a good idea for a post 😉
I personally enjoy using https://steempeak.com which has become my favorite client.
BTW, feel free to vote for me as a witness if you like my work to help the community.