For all three trial judges out there who might be reading this blog - Please either agree with me that that evidence is objectionable or disagree and tell me it is admissible because [fill in the blank].
When you don't explain why the evidence is admissible and only tell me that my argument "goes to the weight of the evidence, Mr. Lammers", my first instinct is to interpret that as "yes, you're correct, it should be excluded but I'm not going to do it and I think the appellate courts are more likely to back me than you." I also take it to mean that that bit of evidence is going to carry every bit of weight the prosecutor wants it to carry with you.
I know it's a terribly unfair way to see things but you must remember that at that moment I am in the heat of battle and not seeing things in a fair light.
[addendum: What brought this to mind is that I am reading a transcript while writing an appeal and the judge did this. As I read it I can see the probable reason for allowing the item into evidence but I don't know if it was the judge's reasoning. All I know is that I was told my argument would only go to the weight (where I expected it to weigh about as much as a gossamer web). I was a wee bit upset at this; still, Client was found not guilty on the charge that evidence related to (on an unrelated statutory argument) so I cannot claim any harm.]