I understand that normally, Ethernet is faster than wireless. I am wondering if 802.11AC will keep that same standard. Will Ethernet still be faster than wireless 802.11ac?
Refer to http://lifehacker.com/5988340/what-is-80211ac-and-will-it-make-my-wi+fi-faster to know more about 802.11AC
Short answer, Ethernet is faster.
Like 802.11, Ethernet is also a set of standards, and according to Wikipedia the fastest standard is 100GB per sec, which is *way* faster than 802.11ac. However, even 1GB Ethernet, which is readily available today, will trump 802.11ac since its speed is *per node*, whereas 802.11ac only offers a (theoretical) speed of 1GB/sec in aggregate, and "only" 500 MB/sec per node. Realistically speaking, on the wired side you are going to be restricted by your latency on the circuitry (switches/router), whereas on WiFi signal quality and the fact that all nodes are sharing the bandwidth (like using a hub) will keep the node speed much lower in most situations.
802.11ac: The Fifth Generation of Wi-Fi Technical White Paper
802.11ac works in the 5GHz frequency band
well you can try http://www.speedtest.net/ to see if for you 802.11ac will be faster than Ethernet
if you send big files Ethernet will be the good choice
It has a THEORETICAL speed comparable to 1GBit/s ethernet but all WiFi systems suffer from speed drop-off with distance and physical obstacles in the way of the signal. They also suffer interference from other electrial sources and contention for bandwidth with other nearby WiFi (or other) transmitters using the same wavelengths.
Cabled ethernet can also suffer degradation but more of the variables are under your control - quality of cabling, the number of devices sharing the system and the profile of their bandwidth usage. So the answer to your question is "probably not".
Another advantage of cable is that it's harder to intercept the signal. The disadvantage is that your end-user device needs to be close to a cable outlet and you've got that trailing cable.