I was happy with the JO signing. Also, I think it's very doubtful that Shaq signs for the minimum if we're still sitting there with the MLE, or a substantial part of it. Shaq envisioned himself as an MLE player, and I don't think we could have sold him on taking less if we had the means to pay him more.
I suppose, in hindsight, that there were better "value" signings. Kurt Thomas has given about what JO has, for a minimum deal. Same thing with Ben Wallace, if he would have left Detroit.
As you said, though, we needed a big man, and we ended up with two of the best on the market. JO to date hasn't worked out, but I'm still pretty happy with our big man rotation, and have faith that JO can contribute later.