Articulation: Well, it seems that Lego have listened to the Fans' opinions on the Hero Factory 1.0 sets and have decided to completely redesign their sets. One of the major changes that had been made are the new limbs. Instead of only having one piece; like with the Hero 1.0s, the Hero 2.0s now have bendable limbs and clip-on armor to match this movement.
Lots of new pieces: The only piece I think is the same as a previous release is the Weapon-Hand-Connector piece and even that is a new mold from 2010. This really shows how Lego have decided to make Hero Factory independent this time around.
Safety and playability: The two Lego-Minifigure Spear pieces have been remade out of a soft rubber and bend easily, making it less threatening and sharp. Also the pieces are a lot larger and redesigned to be a lot less brittle than previous BIONICLE molds. Although the hand looks a little bit hollow and misshapen compared to BIONICLE hands, it seems to be a lot more durable.
Connections: I love the new Ball-Joint-Armor Connection Pieces that have been introduced! They're compatible with any ball joint on the body and look can be moved around more easily. This allows a person to alter the model in the slight ways that make them feel they have improved it and made it unique.
Chest: I love the new torso! It is so sleek and well colored! It really seems more layered and retains many of the best parts of the old torsoes.
Purple: This set is a pretty good source of Purple pieces. It includes a purple spike, a newly-moulded Purple Head-Piece, and a New Purple Hero Core. I've never really liked Purple too much but I think that the contrast with yellow used in this set is brilliant!
Head gear: I think my favourite part of the Hero 2.0 sets are the new Helmets. Not only can you switch head pieces, head-gear pieces, and colored cap pieces, it gives you so many different ways to make new heads, something that BIONICLE never did and something that allows you to create a childhood character from much easier. I also find that the Head Gear used in this particular set reminds me of a previous BIONICLE mask. The aerodynamic Air-Vent tubes on the from remind me of Tanma's Mask, a BIONICLE set released in 2008. I like this connection and it makes Evo's Head Gear piece seem easier to imagine as a character's helmet.
Weapon: While I would have liked a second yellow hand in the set, I am grateful of the pieces that came with the Multi-Tool Blades. I would have liked some nicely colored Light-Saber blades but I suppose the whole 'harpoon-type' effect that the weapon has is equally effective. Also, if you switch the weapon around it looks somewhat similar to a Tazer; something that may be good for MOCing.
Bare back: While I love the torso, I've also noticed that the back has a total of six spare pin holes. It would have looked better if these could have been covered by another piece but it looks exposed. However, this also gives MOCers more freedom when using the torso to build MOCs from, so I can't really complain on that note.
I would definitely recommend getting three particular Heroes; Surge 2.0, Evo 2.0, and Nex 2.0. While Surge remains my favourite Hero Factory set and character, I think that Evo is probably an iconic set in Hero Factory history. He is certainly the most promoted for the Hero 2.0s and I think he manages to pull off the responsibility. 9/10 Get Evo Now.