Thanks to the OP for posting this thread and to all of the replies.
I am in the same position e.g. Worked for 10 years, incapacity benefit, and currently ESA (which I now know is both contribution and income related).
I recently received my migration letter and expect that I will also receive New Style ESA with UC top up. It's all so confusing but I'm so glad I became a member of this site as it has been really useful in helping me to try and decipher all the different terminology etc.
I phoned the UC helpline yesterday and the person I spoke to was really nice but apparently my case is "complex" so he was unable to do a benefits calculation but he is going to look into it and phone me back next week.
Coincidently I received a P60U in the post today, they haven't sent me one since 2020.
