I've just watched part one of The Package on YouTube, and I can state without hesitation that it was awesome! Out of all Legends episodes so far, it's by far the best. The Babysitter and The Duel both had good plot ideas, but they were executed in such a way that canon errors, silly mistakes, and sometimes terrible animation distracted you from the story.
The Package is a lot better - since it's CG rather than cartoon-ish animation, they can do a lot more, including, among other things, a truly incredible space battle.
Stop reading here if you don't want spoilers.
Starting off aboard an ONI Prowler, a team of Spartans, consisting of John-117, Frederic-104, Kelly-087, Arthur-079 and Solomon-069 being briefed by an intelligence officer - a Covenant Fleet is momentarily trapped in the system, and is carrying an important "package," which the Spartans must retrieve. The Prowler de-cloaks and deploys the Spartans in Booster Frames. Solomon is lured into one of the ships, and killed by an Antimatter Charge. Arthur is killed trying to cover Kelly during the battle, as the Spartans lock onto the real target. The film ends with the three surviving Spartans aboard the fleet's flagship, momentarily protected by a Bubble Shield, and attacking the hangar-full of Covenant warriors.
(Yeah, I know, this was culled from The Package article. I'm too lazy to write my own, and it's too good not to be used here)
So yeah, it's a really good film. We do learn several new things: The film gives us our first real picture of a Prowler-class Corvette (The Halo Encyclopedia confirmed that the Prowler is actually the Prowler-class. If anyone wants to change the article any time soon...), and she carries some sort of cloaking device that we haven't seen before, which could be reverse engineered from captured Covenant technology, or maybe the UNSC made it itself - we're getting quite close to invisibility cloaks at the moment. The cloak also appears to be similar to the Bubble Shield when they deactivate it to launch the Spartans, so maybe the cloak is a hologram that's projected onto the inside of the Prowler's shields. Weirdly, the Booster Frames also seem to have shields of some kind, just not the Spartans. That's not an insurmountable problem, perhaps the UNSC hadn't miniturised the shield generators to the extent of being able to fit them into suits yet. They also kindly showed us what a Point Defense Laser looks like, and what it looks like is a Beam Rifle on a mount that is deployed from holes in the hull. The Booster Frames also seem to have some pretty cool weapons, including a Gauss Cannon, which is apparently powerful enough that the combined blasts of two and a lot of missiles can blow through a CAS-class assault carrier's shields, which seems a bit off to me. They also carry some sort of sensor buoy that can attach to Covenant hulls and tell them what's inside, an M41 Vulcan Light Anti-Aircraft Gun that can be manned by a second crew member, some form of anti-Plasma Torpedo countermissile system, and a missile pod that when launched fragments into dozens of smaller missiles, each of which can do serious damage to a Covenant ship. It's a bit odd having such small missiles do such a large amount of damage, but maybe they use Induced Gamma Emission warheads. They also seem to ignore shields. We also get to see that different types of Sangheili and MJOLNIR armour are in widespread use. Kelly wears EVA Armour, and one Elite crew member can be seen wearing what I think is the Flight Harness.
Of course, we do have a couple of problems: "Two more Spartans to add to the ever-increasing list of MIA's/KIA's, throwing the Fall of Reach's number out the window almost gleefully", to quote Specops 306. Covenant Energy Shields seem to be used selectively - missiles will do severe damage to the ships' hulls, but Solomon has to wait until one ship drops its shields to let fighters out before he can fly in to his eventual death. The Spartans are briefed by an ONI Commander before their mission, and he wears exactly the same sort of uniform as Miranda Keyes in Halo 3. He wears three gold stripes on his shoulders and a silver oak leaf on the collar, so a real Commander, and the ONI patch on his upper sleeves, but on his left chest he wears the silver eagle of a Captain, as well as three gold stars just above his stripes. Maybe the eagle is the UNSC Prowler Corps equivalent of the Submarine Dolphins, and the gold stars are equivalent to service stripes, but at the moment we don't know at all.
Just time for a few more nitpicks: The dialogue can be pretty poor at times, with almost zero emotion, but maybe that can be expect from the Spartans. A few of them seemed to have distinctly non-regulation hairstyles, including the ONI Commander, the producers disobeyed the "no stealth in space rule" with the Prowler, but since everyone does that, it's acceptable, and one Elite voice actor sounded terrible, but apart from all of these, The Package is a really good film, and I eagerly await Part 2.