Can somebody tell me about the Kerry Kelly Hemi bit. What type of feel it has.  

Leverage and lift .

I purchased the Hemi for my two finished horses and liked it so much I had to go get the Mini Hemi for my colts.

It provides a quick, clear signal. Instant response. I love it because I can get the attention of a strong horse very easily, but it can also be as light as you want it to be. (I can ride my gelding around with my finger tips; but when its time to run he gets strong and pushes on the bit). 

I have used it both on a stronger pushier horse and on a light horse that just needed some lift. It worked great on both. The stronger horse hates any kind of gag and just feels so comfortable in this bit. It has really helped him finished the back side of turns. I currently run him in the slow twist with a life saver, but don't have the control I need to stop at the end so I am planning on switching to a ported mouthpiece which was recommended by them for more whoa.

I really want to try the mini hemi with the chain port.

I'm really interest in the brass ball curb, what is the difference between it and a regular chain or leather curb? 

You can call them and they are very helpful in explaining the mechanics of their bits. I love my Hemi chain with port and the Magnum. 

Thanks this helps