I have had the same experience with the sierra and speer bullets as well (the hunting versions). They just dont have the BC that these newer bullets have. The bonded bullets are just awesome. These bullets like the accubond and the scirroco II beat the game kings and the speer bullets in ever category hands down.
I would use the scirroco II in the 25-06 but I wish they would make a heavier weight bullet for the .257. The nosler accubond being a 110 gr bullet is about the perfect medium between the light and the heavy .257 bullets. It has awesome expansion and penetrates enough to give you a pass through on deer sized game which will make a easier blood trail to follow if it does run a ways.
I am using the 115 gr VLD for the first time and am gonna try to get a mule deer with it and see how it does on game. I like the trophy size deer as much as anyone else but in the end, I want to eat the meat too. I dont want my bullet tearing up too much of what I want to eat. If this bullet doesn't pass for me then I am going with the accubond for sure.
Just my way of thinking.