I think Gordon is the superior prospect, but since Tulo was drafted by the Rockies it makes it much closer. Tulo has been long compared to Crosby, and a hitter like that at Coors is going to have some good value.
Also, neither prospect has much in front of them and both should start at AA this year. Teahen and Barmes can both be easily moved for these guys, cause in the long run they are much better prospects. One more point, Tulo actually has played professional ball, which Gordon hasn't (I don't count the AFL).