power zoom and power focus are crap esp power focus.
They cannot match with the precision from mechanical focus.
powerzoom is another story, if you don't mind with precision, PZ is ok. However, PF is unacceptable.
Long ago when I first bought my first AF SLR, the minolta 3xi was on my top list. however, when I tried power focus. I just put it down. Unacceptable.
However, if you mean to use AF all the time, i think this lens is great (for its size).