I think it's a great signing for West Ham. The boy is class when fit. Genuine guile and creativity, can drive at defenders and spells last season showed he had learned to do the dirty work without the ball as well. He'd have been in my World Cup squad at the expense of Welbeck, and in my starting XI if firing, instead of either Alli or Lingard.
On a free transfer and, you'd think, a salary or salary structure which reflects his poor injury record, it's not far from a no-lose situation for West Ham.