Sir, I would avoid the 552 EO tech, only becuase the battery terminals get loose after awhile. I was the second gen owner of mine that had this issue, so I cant speculate on how fast this happens. However, if you do go for the EO tech, Kyle Defoor offers some tips on how to go about fixing this flaw. Link below:
http://www.kyledefoor.com/2009/12/mo...ch-secret.html
I actually sold the 552 that I had and am replacing it with an Aimpoint 4MOA dot T-1 Micro.
HTH