Mac as wi-fi hotspot: how many devices can connect?
On OSX Yosemite (beta 10.10.3), on MacBook Pro (13-inch, Mid 2012), today (2015-04-28), I've connected 15 different devices (Android, iOS, Win, OSX) via WiFi hotspot (sharing internet via Ethernet), and reported very low decline in internet bandwith with each new device connected.