802.11ac, any advantage in public wifi setting?

[precip9]

The advantage of 802.11ac is obvious in the home, transferring files around the house on a gigabit network. The advantage in a Starbucks, or other public venue, is questionable.

With the Speakeasy speed test, the highest speeds I've ever measured on public, or institutional wifi, are at the School of Visual Arts in NYC, about 50mb/s. Sometimes hospitals offer very fast connections, a side-effect of their massive data needs.

Until a few years ago, all Starbucks stores had a single AT&T "T1" line. The "T1" line is an antiquated standard for a 1.5mb/s data pipe. It was shared by all the users in a store. I have been in faster stores, but they were later throttled to much lower speeds. Thankfully, Starbucks booted AT&T, and switched to Google, who are providing a 15mb/s pipe. There is something called "Google Fiber", offering gigabit speeds, but these are pilots. Chances are you'll never be in a wifi hotspot with a 1GB/second downlink.

Since even a 2x1 802.11n card typically connects at 150mb/s, an upgrade to 802.11ac seems like massive overkill.

Has anyone experienced a real, verifiable advantage that would contradict the above reasoning?