He is very similar to Tim Cahill. They had remarkably similar attributed (though Cahill was probably better in the air, Naismith is probably a bit more creative).
I know everyone rightly views Cahill now as a legend. However especially towards the end of his career he received quite a bit of criticism. The moral of the story was that he didn't need to start every game, but in particular games he would be very useful.
I think it's the same for Naismith. Against any of the top 5 or 6 sides where creativity required is not at a premium he is a fantastic asset. He also has the potential to be a bit of a Solskiaar for us coming off the bench in other games.
I think Roberto understands that, and his value as a squad asset. Kendall's column was spot on earlier in the week as well. He is a vital asset, and even if we'd have got 8 million for him, who could we have got who would be happy to be as an effective a squad man as Naismith?