I have direct payments/personal assistant for my sons. 8 hours a week. I had to interview a few people (with the help of my Social Worker) and between us we worked out what the PA was happy to do and what I wanted.
I basically wanted a break! So, 2 days a week she collects my (NT) daughter from school, waits for the boys to come home on the SN school bus, cooks them tea, and baths them. She puts my washing on and hangs it up (I never asked her to do this, but she likes to be busy).
I use the spare time to go to the cinema, shop, meet friends without being tied to school hour pick ups. Now and again, she'll agree to do a bit of a late night - if I've got enough hours saved up.
Some people use the PA to help them take their child out - go swimming, whatever. It's down to what you need and agree. I probably sound a little selfish but I'm a single parent so EVERYTHING else is my responsibility for the rest of the time she's not there.
It's the best thing I've ever done. I was worried about my sons accepting her (one is ASD but not formally assessed yet), but all my kids love her. She's an angel!