The website HDMI.org, in its discussion of "active" versus "passive" cables states that "active cables have built-in electronics to enable long cable runs, and typically these cable require a power supply." To us, that seems like a huge pain (and certainly hurts any notion of portability), RedMere's chip requires no external power supply, and RedMere says that cables with the chip are being made up to 50 feet in length, easily surpassing HDMI.org's acknowledgment of standard cables hitting a maximum of 10 meters (roughly 33 feet).
Not having tested a vast array of powered/active cables, we will not suggest here that RedMere is the only choice. What we will say is that we are incredibly impressed with the look, heft, and portability of what their chip makes possible. Outside of a potential increase in price in order to get such a cable (you'll have to do your own research on how various brands of RedMere-powered cables compare to passive cables), there seems no downside to having such a cable. We, in fact, have a laptop with an HDMI out and it will be great to be able to hook it up to TVs and other entertainment systems when we're on the go without really losing space in our already tightly squeezed laptop bag.
In the end, with the ability to run a longer distance at a lighter weight and be more flexible, all without losing signal strength, RedMere seems to make active HDMI cables hit two of the smaller, faster, cheaper, better criteria (and even if it isn't faster, it's not slower). This really makes an active HDMI cable something worth looking into the next time you're in the market for an HDMI solution.