May I present counter evidence?
All taken from my last game played. All stickied. Only Elites were harmed in the making of this gallery.
http://i19.photobucket.com/albums/b177/iamnotevilness/reach_1111384_Medium.jpg[/IMG
[IMG]http://i19.photobucket.com/albums/b177/iamnotevilness/reach_1111354_Medium.jpg[/IMG
[IMG]http://i19.photobucket.com/albums/b177/iamnotevilness/reach_1111355_Medium.jpg[/IMG
[IMG]http://i19.photobucket.com/albums/b177/iamnotevilness/reach_1111385_Medium.jpg[/IMG
[IMG]http://i19.photobucket.com/albums/b177/iamnotevilness/reach_1111352_Medium.jpg[/IMG
[IMG]http://i19.photobucket.com/albums/b177/iamnotevilness/reach_1111353_Medium.jpg[/IMG[/QUOTE]
Uh, none of those are near or on the head. My pictures clearly show the plasma grenade touching the elite's head like it's not even there.
[url=http://www.bungie.net/Stats/Reach/FileDetails.aspx?fid=238169]This[/url] picture clearly shows you can stick an Elite on at least one side of their head. This isn't limited to sticky grenades, though, this also happens to me with the grenade launcher.
I've also seen others on here talk about the exact same thing - plasma grenades go right through an Elite's torso.
[QUOTE=Kapura]Epiphany: Perceived balance issues with Invasion occur because it is a one sided, one round gametype. It would be akin to playing a single round of one flag, except that it gets progressively difficult for the attackers to score the closer they get to base. If this were a multi-rounded gametype (which it looks to be at retail), there would be even less complaints about it than there are about current round-based objective games. Why? Because there is gradation in winning. One team may capture only the ship as elites, while the other may unlock the core. In the single-rounded version, both of those count as a loss. But in a multi-rounded variant, it would be obvious the second team would have won, as they had scored two out of the possible three points, while the first team had only scraped one.
tl;dr it's gun b k[/QUOTE]
There are balance issues that fall outside of your epiphany, such as there being too many anti-vehicle weapons and grenade launcher starts.