Ditto on all the above, and base running is the more important IMO. Pure speed can help a guy's batting average, especially when coupled with high contact ratings. When stealing bases, a guy is not going to be a benefit with steals unless his base running ability is at 70 or higher, regardless of speed. When looking at steals, it is about percentage, a good base stealer needs to be safe on his attempts at about 85% of the time, or he is sitting at a wash in terms of runs created, or negative effect.
You can have 65 stolen bases, but if you are only safe 65% of the time, the guy is wasting his time running. I would rather have a guy steal 25 and be 90% safe.