I think I saw a thread on this, but it was very old, like 2011, so I'm bringing it back up.
The whole point of a "Full Row" selection mode is to select a full row. Not a cell. I know, you highlight the whole row. But there's still a box around a "current cell". As well, keyboard navigation is whacked now. Using the left/right arrow keys should either do nothing, or better yet move the selection row by row. What happens now is that this "current cell" box moves with the left/right arrow keys. Not fun in a grid with 30 columns :( Extended selection mode is also problematic if you are holding down the Shift key and accidentally press a left/right arrow key.
Can we make SelectionUnit=FullRow actually be "Full Row"?
(I've also got EditTriggers set to None, so I have no plans on making any cell editable, in case you were wondering.)