I use C4 in this game, never used it for anything but as a mine in the past games, but in this game head on fights always frustrate me with the shoddy connectivity and hitboxes, so I use it to flush out campers or injure people I'm about to fight. Flak jacket stops it in it's tracks, I used the assault shield with 2 C-4 once for domination and couldn't kill a guy with two C-4s right under his belly when he tried to cap a flag I was defending.
Overall, I think there are many more issues in this game more dire than C-4. But if those were ever fixed it'd make judging fairness easier and allow people to tell when something is OP. Instead of just overused.
Leaving it as a "tactical mine" on something like an objective or high traffic room rarely works imo since said spots see regular explosions and would blow up the C4 anyway. The throwing distance isn't that bad, the first Black Ops had super tossing distances plus you got two packs of them. Black Ops 1 is where I really got into C4 and in MW3, C4 was the only worthwhile "offensive" equipment.
C4 wouldn't bug me if it couldn't be thrown so far when you can detonate it relatively quickly as soon as you lob it into the room/around the corner in question you are going to storm into. Any of the other explosive grenades I could get out of the way of, while with the C4 once it pops into the room I won't have enough time to get out of there.
GT: Boomer and Tank Pretty darn confident..... I don't want to have to wait till the Microendony XBOXS 4ii comes out another 15 years later....