I did it for a short period. It wasn't for me although I didn't hate it or think it was awful.
The job is basically asking people quite formulaic questions about how well they can manage a series of activities (such as cooking, washing, managing money etc) and how their condition(s) impact their ability to do them.
You write down what they say and then once you've finished speaking with them you make a recommendation based on what they've said, your clinical knowledge of the condition, their medical evidence and medications to say how much support you feel they need in each area (how many points they score). Reports get sent to the DWP who make the final decision on what to award.
Lots of reports get internally audited so you end up getting back things with requests to change recommendations you've made and an explanation of why. It's not usually too time consuming.
3 reports a day is a good number. Some places ask you to do 4 which is probably too many as some people provide 100+ pieces of medical evidence and you have to read them all.
You need to be a good listener, able to type quickly and accurately, ideally while talking. You need to have a broad understanding of a wide variety of conditions and medications. You need to have empathy for people and be able to give them time to try and understand exactly how their conditions affect them. You also need to be able to make fair judgements of evidence, taking into account various factors.
I never felt pressure to give negative recommendations, the only targets were for the quality / timeliness of reports. The people I worked with I felt wanted to do their best to make sure those qualified got awarded the benefit.
It was frustrating at times when I couldn't make a recommendation I might have wanted to - for example, I might have seen a person and believed they probably were quite anxious as they had said but they had never seen a counsellor or specialist and were prescribed only the lowest dose of an antidepressants, and had managed to get out to the appointment (although it was probably really hard for them) no other medications tried, so I couldn't justify a recommendation that they needed significant support because I had nothing to back up my opinion.
I left because it just didn't feel like nursing for me and I needed to get back to being with people.