I had a student midwife with my last pregnancy. She was brilliant!!! I went through a birth centre, so saw the same 4 midwives the whole pregnancy. The student midwife would come in specifically to attend my appointments if she had the day off, she always made me feel comfortable. She conducted many of the appointments herself (main midwife supervised), and when I went into labour she was the one who delivered DD3. She also did daily home visits for the first week.
I found it so lovely having her share this special time with us. If we were having another baby I wouldn't hesitate to have a student midwife again.
ETA- she came to a couple of appointments prior to her asking of I would be willing to have her as my midwife.