Eagle Strike on Vieri de Pazzi
http://www.youtube.com/watch?v=o257rFrSGBc
i don't know if it can be called an Eagle Strike because Ezio can't assassinate him on the floor after the air tackle... its strange because this method work perfectly with Uberto Alberti and should have been the same with Vieri, I pressed the attack button quickly after the air tackle but nothing happened ...
Once you tackle him to the ground, is it possible to assassinate him like Uberto?
No, its not possible... 
It's possible, I've done it before. 
What I did was climb behind Vieri so that him and his guards won't see me. I locked on to him, climbed up, tackled and assassinated. So try locking onto him while you tackle. If that doesn't work try killing with a sword, mace, or dagger. And good video by the way, you are one of the few people to discover an eagle strike on a target. 
Do you use a dvd recorder?
I play on xbox 360 and use Easycap to record videos 
So how do you get Easycap and how much does it cost? Please say, I also play on an xbox 360.
You can find it on Ebay... i paid 10 USD
http://shop.ebay.com/?_from=R40&_trksid=p3907.m570.l1313&_nkw=easycap&_s...
You also need x3 RCA Splitters (1 male to 2 female):
http://cgi.ebay.com/RCA-AV-Audio-Y-Splitter-Plug-Adapter-1-Male-2-Female...
and a RCA cable:
http://shop.ebay.com/i.html?_nkw=rca+cable&_sacat=0&_odkw=rca+cable+doub...
This is the Setup:
http://www.youtube.com/watch?v=bc0_EMwnZak&feature=related
For other questions send me a pm
When I first started recording I didnt have splitters... if you dont buy those you gotta record looking at your PC