I have used both (childminder and nursery), and if I were to start again, then I'd probably use a childminder.
My DD1 went to nursery, whilst she liked it, she never loved it iyswim. This was an ofsted outstanding nursery as well, btw.
DD2 on the other hand loves her childminder. She has not been all summer and when I told her this morning she was going back to the CM, she jumped up and down with excitement and shouted Hurrah. She regularly says "I love, DD1, Mummy, Daddy, Nanny, Grandad and my CM". There is a bond there that DD1 never gained from her nursery. I think the CM will remain a part of our lives for a long time to come.
The other benefit I have found to using a CM is that because she is in the local community, all her children are going to the same preschool (and later, school) as my DD. Whereas with my DD1, although she went to the nearest nursery to us, only one other child came up to her school from the nursery.
The downside I have found is that as children get older, it doesn't get any cheaper. The childcare vouchers that I would have got as a discount on the nursery fees is now used to pay for the preschool that DD goes to. I still have to pay for the childminder for the morning that DD is at preschool as the Cm takes and collects her - so it is now more expensive than a nursery iyswim!
Lots of people raise the questions about sickness - but in the three years I have used the CM, she hasn't yet had a day off sick... and other friends I know who use CMs also say this is very rare as when they don't CM, they don't get paid - hence the fact they don't tend to take time off unless they really need to.
My experience of using a CM has been extremely positive and my DDs love going to the CM. DD1 would prefer it if I worked more so she could go to the CM once a week, as she told me today! It is lovely having another adult like her in children's lives. HTH