He is still good as you have just been presented with an ugly guess and good players excel at that. Is partner capable of doubling with 2 A in the unbid suit? If not I would risk 4♠ as there are many hands that make with a fit and any 2 of AK♠, A♥,A♣ certainly even [hv=s=sxxxxxhxxdxxxcaqx]133|100|[/hv] has odds on play