IMO it is just like grunting tactics or elk bugling tactics... The more aggressive calling will bring in more aggressive animals. Now not all big bucks are aggressive, I rattled in a 208" 19pt non typ 3yrs ago by simply tickling tips of the tines... and he was more curious than looking for a fight. For me, rattling will bring in your more dominant animals, however, dominant animals have a higher tendency to have busted up racks than sub-dominant mature bucks that make better lovers than fighters... They are just like people in this respect. I know some pretty big dudes that wouldn't hurt a fly, and a few scrawny ones that you don't want to look at the wrong way, if you catch my drift ! Any horns will work, but I like to keep my rattling horns around 55" with long tines/heavy beams, I get good sound out of them, and I can get mutiple tones by using differnt parts of the antler. This allows me to read a bucks body language while calling with rattling horns, given I can see the animal as I call. Blind rattling is just as risky as blind grunting, You may have a monster just out of sight that hears your rattling and wants no part of a fight. Also, bucks that respond to rattling will almost always come in on the downwind side to identify their opponents, if you are not on top of your scent control, then this may not work well ! Its all in what you like to use. Good luck.