The Raspberry Pi is very popular, but I doubt it is suitable for education: It runs Linux, which is a highly complex piece of software. Beginners should learn from ground up, for example using AVR assembly, then C, first fundamentally understanding the machine, the peripherals, and storage. THEN it may make sense to debate which distribution is the best. Ardurinos are more suitable 'cause closer to the metal.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.