I prefer the Katana for its curved blade and its agility. A Kalij, Scimitar, Talwar all have curved blades too but only use one hand and lack in my opinion the flexibility of the katana. The Hanwei Shinto Elite 2 lbs 11oz is a perfect compromise for cutting power, handling, agility, and weight. It was designed for cutting tatami omote which depending on the thickness of the rolled mats can similulate a human limb or a torso when properly soaked in water. While I own a Hanwei Shinto 1 lb 11oz it has a Bo Hi, the wide groove between the shinogi and the mune of the blade which makes for a fast, agile, and very quick blade capable of making very quick cuts I prefer the more traditional profile of the heavier blade of the Shinto Elite for cutting.
Since cutting one's opponent is sine qua non of the exercise, it is not how quickly several cuts can be made but how lethal the cut is when it is made. A curved blade cuts better and a curved, heavier blade digs in deeper as it cuts due to its weight. While weight is an asset it can also be too much.
I have a Cheness Specialized Goza Cutter which is a heavy blade designed for heavy cutting. I have cut with it and it will cut very well but it is a slow handling blade. Not clumsy mind you , but heavy compared to a regular katana.
Both the Hanwei Shinto and Shinto Elite are made from T10 steel and both are differentially tempered. THese blades are made in about the same way as the New Sword period (beginning 1500 AD).
I have attached a couple of pictures. The first shows the Shinto Elite (nearest katana, Shinto, and Cheness SGC) and the next picture shows the Cheness SBG.



