It's not listed on Ghost Recon Network's Battle Crates page, but the 416 is also available from Spec Ops Crates as a Legendary drop. You can get it for "free" by collecting enough Prestige Crates.
You can hand in every 20 Prestige Crates for a free Battle Crate (Spec Ops; Ghost War) of your choice. Since the start of the new daily challenges in SO4, I've collected 14 Spec Ops Crates entirely for free.
Anyway, the 416 is a high-tier 5.56 assault rifle but it's about the same as its peers like the MDR; TAR-21; M16; M4A1; MK18; and LVOA-C the way I usually spec my assault rifles:
Where it beats its peers is in accessories selection, since it has the 50 round magazine (M16; MK18 cannot) and it has the full range of barrels from short to long (its peers either have no extras or standard+long).
I also use the HK416, but for aesthetic reasons since it's roughly the same length as the MK14 while both use the standard barrel. Not a fan of the M4A1's looks; the bullpups are too short, and the M16 is too long.
Performance-wise, it's okay but suffers from noticeably worse horizontal recoil compared to the LVOA-C or TAR-21.
