No one who will be available at 29 is likely to make an impact. There will likely be a group of receivers available at that point who are about the same, and all second-round quality. It makes sense to wait ten picks and get the same calibre receiver at 39, if you're going to draft a receiver on day one at all. On the other hand, we also really need a passrusher, and there may be only one available at that point.
Regarding Jackson, he's 5' 9 3/4", 169 lbs. My concern would be that the first big hit would send him to the DL. On the other hand, he is extremely fast. Can we afford to spend a first-round pick on a slot receiver who may be nothing more than a great return man in the NFL? On the other hand, can we pass on such a dynamic playmaker when we have such a lethargic offense? I dunno.