This thread starts with the assumption that Cal is not going to get the all-world big man we're lusting after, ala Sullinger.
In his absence, the tendency has been to look for agile-but-thin guys who appear to have some hand-eye coordination, and hope they can bulk up. That would more or describe, I think, Bak, Behrens, Solomon and Kravish. Harper was like that as well, although he got stronger during his career, and also was able to use good technique to make up for his lack of bulk on the boards. Of the other four, Bak is so far the major disappointment. IMHO, that's mostly because so much of his off-season improvement time was lost due to his regular visa difficulties.
That pattern was broken with Thurman, who has a bigger body, some ball handling skills, but is not as quick as the previous four. He's more in the Wisconsin-style bruiser mode.
At this point, assuming we can't have the best of both worlds, would you prefer getting the bigger body, hoping he can grow into it in terms of agility and post technique?