After a little research and asking around I finally found out that the Alien was in fact a type of camming device produced by Colorado Custom Hardware (CCH), available only in the USA and that was as far as my knowledge extended until very recently when Aliens cams became readily available in the U.K through Penrith based APEX distribution.
Until seeing one in the flesh (the cams not the ones in the spaceship), all I understood was that they would fit in places other cams simply would not, such as shot holes, small pockets and peg scars. An ingenious design putting the springs inside the head of the cam drastically reduces length of the head of the cam, resulting in 3CU width and 4CU holding power in a light, flexible, single stem design. This is most evident in the green alien and upwards sizes. The looped design on the end of the unit allows the sling to float easily and works with the very flexible stem to reduce the chances of the cam walking.
A slightly softer alloy (6061-T6) than that used by most other cam manufactures is used on the cam lobes to give an increase in the cams bite when it is loaded, reducing the shock load on the placement (the rock) in turn. I have witnessed the result of this softer alloy at work having seen a friend's cam that had taken a huge fall and held, in its melted state afterwards. The cam had deformed clearly dissipating some of the force in the process. This does however mean that the cams wear a little quicker than others and this is evident in my Aliens when compared to my other cams that are significantly older.
One factor I have found slightly annoying with one of my cams is the tendency for the wire connecting the trigger to the cam lobes to slide around if it gets caught in other gear on my harness, meaning the cam cannot be placed quickly without re-setting. This has not happened to me in a moment of desperation yet but it could be serious if it did. However CCH will be using fixed pins instead of wires on all the new units so this problem should be eliminated.
The cams do not have machined cam stops so have no passive strength, i.e they cannot be used like a wire or hex. A friend once told me a story of some one falling off when winter climbing onto a cam that held. Upon climbing up to the high point they found the cam had walked into the back of the placement, and had held one side on rock and the other dug into frozen turf. If the cam had not had passive strength the placement would have ripped. It is therefore important to ensure the placement is as unlikely to walk as can be made possible. The looped enclosure and flexible stem will also help reduce the chance of this.
In conclusion the bottom line for me is that these cams will fit into places that other cams wouldn't, turning those marginal placements that wont quite fit into bombproof, confidence inspiring runners. In this aspect the cams seem unbeatable. However they do seem to have a few down sides those being durability and lack of passive strength. For me however the increase in placement options and performance are worth the sacrifice.
My personal choice for a cam rack would be Aliens black to red as this is where I feel the cams really come into their own due to the smaller nature of the placements and other cams above those sizes (a red Alien is roughly Wild Country Friend 1) due to the increased durability. See a size chart at www.aliencamsbycch.com/products
Find out more at www.aliencamsbycch.com and at UKClimbing.com's Product News, click, ALIENS. There are also several discussions at UKClimbing.com about Alien pricing and a recall by CCH. You can view these discussions here.
He has been climbing for six years and for the last three could quite possibly could be described as obsessive! He has climbed Bowfell buttress in full-on winter conditons with a very shady rack and has a soft spot for Black Crag, Langdale. crag. Favourite routes include the Moon at Gogarth, Spartacus on Kalymnos, and the North Face of the Trioat (Argentiere Galcier).