Booker was slightly younger his freshman year than Murray is now, but I think Murray has had a considerably better freshman year than Booker had last year.
Booker was a spot up shooter who spaced the floor for Kentucky. Murray is the first option and about to set the record for freshman scoring in a season at Kentucky. Booker got most of his offense in transition and spotting up. Murray gets most of his offense running off screen and taking contested shots, if Murray isn't able to do what he is doing now then the offense simply doesn't run.
I like Booker, but I think Murray is going to be a much better pro, because his feel as a scorer is better than Booker's was at a similar time of his life.