Alien cams are legendary among dedicated trad climbers, and have gone mostly unchanged since the early days of Colorado Custom Hardware, until now.
Cue my Pavlovian response where my hands begin to sweat and I look up the closest gear shop.
The biggest new features that stood out to me are the narrower head profile and the drop in weight. The head of the cam is 20% narrower than traditional Aliens, making them even more effective at fitting into shallow crack placements. The head profile of the four cam Evolution is comparable to a Black Diamond C3 with three cams. In addition, all of the Evolutions dropped about 25% of the weight of the older version, making them significantly lighter than similar small cams such as the Metolius Master Cams or Black Diamond X4s.
They had me at "new Alien cam". Good review here if you want to do your homework and aren't going to go out and buy the next new Alien cam you can get your hands on, like me.