The real issue about where Giddens and Walker should play next year has more to do with their talent level, BBIQ, and grasp of BB fundamentals. Neither the DL nor Europe will give either player a true "taste" of the NBA game as both sites aren't representative of the senior league.
Both draftees have outstanding athleticism yet neither player has world-class athleticism. That said we should focus on their strengths and not belabor their lack of "freakish" athleticism as though this one feature dooms their NBA chances.
I'm anxious to see what handles Giddens has and whether he knows how to use his body to shield his dribble (something Pruitt has yet to master). Until we see how Walker and Giddens respond to NBA competition we're all just guessing about where they should play and whether they are NBA "ready".
I think the Giddens and Walker comparisons don't necessarily bear merit. Giddens is 23, older than Davis, Pruitt, O'Bryant, and Rondo. He played a lot of college ball. Plus, while it'd be nice if he had a great handle, it's not like Posey was taking players off the dribble very often. All we really need him to do is play tough defense and hit the open three. If he can do that--and most scouting reports think he can--he might help mitigate the loss of Posey.
As for Walker, his ceiling might be higher, but he's also younger, has less college experience, and apparently a worse shot. While he may have more potential to be a game-changing star, I'm less convinced of his ability to immediately fit into this team where that skill isn't exactly needed right now.