Deathadder is hard as hell to use for fingergrip... as far as Razer products go, Salmosa (has a low DPI though), Abyssus, and that new mouse are really good for fingergrip. I'm using an Abyssus myself for finer grip at the moment, no complaints with it.
DA is a big mouse imo. If your hand is big enough though it's a great mouse.
DA is maybe not great for finger-tipping, but it's not bad for claw-gripping:
Very nice informative video. Small tip,(I do the same thing in videos) there is a lot of studding at least in the beginning, try writing some notes.
. (not saying I am one to talk but I do the same thing).
Looks very comfortable to "claw-grip" and even "finger-tip grip". That mouse looks too small to palm, at least with my hands. My old mouse was the Logitech Performance MX and boy did I fingertip that mouse when things got intense. If your fingers are large enough to arc over the mouse then it is a finger-tip mouse.(Some of you may say I am wrong but I held that mouse all three ways.)
I think a factor that a lot of people forget is the actuation force of the mouse button itself.(which isn't the only factor of course). The lighter it is to click the mouse the further back you can hold it. I could actuate my Performance MX from pretty far back which means I could finger-tip my mouse If I held it far back enough. It was a very precise mouse too. I would say the bigger your hand, the more mouses you can finger-tip.(girl-hands probably couldn't fingertip it)
The arc of the mouse seems to be important. Not too big and not too small. I had the Performance MX Which had a large arc that tilted to the right a little bit.(That was a little too steep for me.) One of the current mouses I have is the Razer Abysuss and that is very flat. Without a natural downward arc it takes quite a bit of energy to focus around the mouse. Although Finger-tipping is the only way to hold an Abyssus, I don't do my normal finger-tipping. I normally like to use my thumb and pinky to throw my mouse around. With the square-ish form factor it is not what I do, I move my whole arm more or less than just a flick of my thumb and pinky.
Another factor would be weight and not just over-all weight, but where it is distributed. Where the most weight is, is where is will turn from. Also the distance of the laser or optical sensor from the turning point.
I have the Razer Lachesis and it is very hard for me to fingertip the mouse because the mouse is so long and so flat on the top. The weight of the mouse is at the back and the laser is further back than front. If I were to Fingertip this mouse using my favorite method(thumb and pinky twisting) I would move very awkward and not that percise. If I moved my fingers up more I would simply not be able to Finger-tip grip due to the back of the mouse hitting my palm.(Itwould have to be a palm grip)
I know that some people may not agree or use the same hand-grip/movement-style that I use, but that is just my thought and observation.
So overall, everyone's hands are different in size and positioning preference.