OpenSignal, by means of mobile apps for iOS and Android, has been amassing data on Wi-Fi and cell-network signal strength. They released yesterday a few of their findings on the speed of Wi-Fi available at U.S. chain hotels
(download speeds, specifically). Though it shouldn't be surprising that (as their data shows) more expensive hotels generally have faster speeds, I know it hasn't always matched my own experience. (Hotel chains also vary, even within brands, in whether the in-room Wi-Fi is free, cheap, or exorbitant.) If the in-room connection is flaky or expensive, though, from the same report it seems you'll do better by popping into a Google-networked Starbucks location than one fed by AT&T, and McDonalds beats Panera Bread by quite a bit.