I really did not want to get into this discusssion but I guess I have to throw in my 2 cents.
First, I would like Phoenix to keep their starting five if reasonably possible. They all play with heart which is hard to find in most players, especially Nash, Marion, Q, Amare and Johnson although Joe is less demonstrative. This does not mean he does not play with just as much heart.
The only way I would explore a trade with Denver or any other team for a big man plus change would be if JJ's market value is simply too high. I was worried about this issue even before the season began.
Joe Johnson has proven to me he is a gamer and a multi-positional player. He not only proven he can play at least three positions (PG. SG and SF). Also when I look at his build, I sometimes almost confuse him with Amare... yes, I think he could also play PF in a pinch.
My bottom line is keep our starting five at all costs and only trade JJ if it becomes unreasonable to keep him because of an excessive contract offer. I would want alot in a sign and trade with Denver or any other team... much more than, e.g., Nene, who is still inproven/injured and Leonard.
Keep our starting five and just add some role players and draft picks.
I agree with other posts that would trade the Chicago pick for a proven center but I don't think the Suns would even have to this. Don't the Suns have like a MLE.