Part of the slow uptake until now has been standards related. Although some access points have supported the new 802.11ac standard for more than a year — I bought one in November 2012 — the official standard is generally stable. Hardware makers can build and sell 802.11ac routers with much less fear of incompatible devices than they could when I bought my device.
So what can you expect if you do buy an 802.11ac access point or router? Based on my experience, a nice speed boost to begin with as shown by my Moto X below.
You’ll need mobile devices that can support the standard of course, and based on the few that I have, I often see the full bandwidth of my wired home internet connection on my phones and tablets. I pay for 75 Mbps Verizon FiOS service, for example, and I typically see wireless transfers well above 70 Mbps from my router when I’m a room away or less. Across the home and down one floor, the speeds drop noticeably, but signal strength and speeds are still markedly better than from my old 802.11n router.
As far as what devices support 802.11ac, the list is growing but still small. As mentioned the Moto X is one, as are many of Samsung’s Galaxy phones from mid-2013 onward, the HTC One, and others. Sadly my iPad Air can’t take full advantage of this wireless technology but ‘d expect future Apple devices and phones from others to start including 802.11ac support now that the standard is approved.