IVs for Robin (M)

I was thinking on making my own challenge for the lategame, which is promote a unit to 5* and merge it +10. I decided to make it with Robin because: 1) is one of my favourite main characters (behind Ike and Xander) and 2) is easier to get than the other two.
Well, the point is that between my 6 3* Robin, the most interesting are the one with +Spd -Atk and the one with +Def -HP. Both are not the best IVs for him (or at least it is what I think), but if you have to choose between them, who would you choose?