Yavin 4 has seen quite a decent chunk of changes since it was first released in 3.0, from reducing the lag - although this could be said about the game as a whole - to finally fixing the Revan fight. 3.0.2 brought in yet further changes, and they're really quite fun.
Firstly, the Weekly Mission, Spirit of Cooperation, has had its rewards altered. Now, as well as the two Purple Reputation Tokens, the mission presents you a choice of box which contains level 55 gear for companions. These boxes initially seem to require one specific companion to be 'used'. For example, one might imagine that the gear within "Corso Rigg's Defense Gear Lockbox" might only have gear Corso and Corso alone can use.
The truth is much more welcoming.
The gear within the Lockboxes - including Earpieces and Implants! - is all Bind on Legacy and, once you get through the box-opening, can be given to all companions who have the same stats and fulfil the same role across the game. Got an Agent you need to level up from 55? Just gift them the gear from Corso's box and Kaliyo can use it!
As with the weapons given to us throughout Rishi and again with the Enemy Within weekly mission, the rating on these items is 192, which is of course an invaluable upgrade above most armour sets at 55. Due to the armours' non-optimal stats, though, a fully-augmented and optimised companion in 180/186 mix will still return higher damage/healing output at the cost of health and armour, so the two cancel themselves out. If you do not have a certain companion geared in any shape or form, and need them for Achievements (seriously, this Expansion has provided the best opportunity to do so), then these armour sets are not to be sniffed at.
There does remain the question and potential issue of initial availability. We know that the sets are given via the Yavin 4 Weekly mission, which of course is unlocked after every single mission - including defeating Revan - is complete. For someone who has completed the story on eight characters, this provides no problem; just complete the weekly, get all the sets, done. However, for someone who has not yet even started the expansion's story, these armour sets would be a very nice boost to help get them started. After all, one already receives the weapons with the Revan Prelude, so the armour sets should be the next logical step. I do not yet know whether these sets can be attained any earlier as a one-time reward with these changes, so I shall endeavour to investigate in future.
The next bout of changes really are very interesting, particularly for me as an Ancient Historian and Lore geek.
When you traverse across Yavin 4 now, you have the chance to come across some individuals who one might say are high spirited, and very clear in their goals, although you may be able to see right through them whilst they are preaching.
To cut the puns short, there are four ghosts on Yavin 4. These ghosts represent the Ancient Sith of Marka Ragnos, Naga Sadow, Exar Kun, and Tulak Hord. Veteran SWTOR players will know Tulak Hord directly from the Inquisitor and Warrior storylines (more so the Inquisitor), but the others have just been relagated to a tomb (Sadow and Ragnos), and armour sets on the Cartel Market (all four) without any more direct reference, beyond Sadow's statue just before the entrance to the Temple of Sacrifice. Marka Ragnos has been realised in another Star Wars game, that being Jedi Knight: Jedi Academy, where he was just as ghostly. It was also the first time that a Sith Pureblood had been visually realised in any multimedia, I believe. This marks Sadow and Kun's first actual "appearance" anywhere outside of books and comics.
Regardless of who appears where and how often, it's great to see the Lore delved into, although the Sith do nothing more than "[Eerie Whispers]" and leaving a Force Echo on players, as well as granting an Achievement which explains just a little bit more about their fame with the occasional in-game twist ("Visited the Ghost of Vitiate's Master", for example). These Force Echoes allow you to then read their Talismans, which you need to find around the whole of Yavin 4. Curiously, Sadow's talisman is the only one not in the form of a tablet; his is apparently his helmet, which is bizarre but pretty neat as well.
There is also a fifth Talisman beyond those of the four Sith Lords. This Talisman is just a teeny-tiny bit more volatile than any of the others, considering that when properly activated, it just so happens to summon forth a gigantic purple swirling vortex of doom. Said gigantic purple swirling vortex of doom requires a further buff from a certain object in Tatooine's Outlaw's Den to even harm, as well as a sixteen-man-group; and yes, all members need the Tatooine buff, or else the gigantic purple swirling vortex of doom shall massacre everyone with ease.
I really do like what they've done with the ghosts and the gigantic purple swirling vortex of doom; whilst it's a shame that you only have to go between two planets (also factoring in the time for a couple of people to get the Talisman buffs, just in case), it is nice that they now have something new that requires traversing between planets to be accomplished.