Of the four 2.0 releases of the Outer Space Men figures, Inferno is unquestionably the most compelling. Along with Metamorpho, these two look significantly different, particularly when compared to the original 2010 release.
Previously, Inferno was cast in silver plastic and painted in the colors you see, with an opaque flame, gun, and head. This time around the figure is a mix of silver plastic and clear yellowish orange plastic. Take note of the feet, hands, gun, chest, chest jewel, head, helmet, and flame as all of these are actually painted clear yellow, while the other body parts are opaque silver. Because of the high quality paint job, it's actually really hard to tell these are different colored plastics unless you shine a bright light through them. If a tiny little bit of light didn't peek out through the chest, I'd never notice!
If you ever get the chance to buy these individually, get Inferno first. The clear red, plus the clear areas on the back of the torso and helmet allow light to shine through so even packaged collectors can enjoy the new lighting feature. The set of four 2.0 figures is $50 at Store Horsemen.
Overall I'd say the set is an improvement, although perhaps not one enough to warrant another $50 on the set. If you were dragging your feet before, or missed the first round, these are probably the best ones to get.
One final note-- series creator Mel Birnkrant himself posted a confirmation that the 2011 figures of Mystron, Electron+, Alpha 7, and Commander Comet would not get a 2.0 release as the originals were already more or less perfect. (I agree.)