What I love about Lego WeDo kits as opposed to Lego Mindstorms is how "out of the box ready" they are. Keep in mind LegoWeDos are geared for lower elementary school students but they can still serve as an introductory lesson for middle school students.
In February, we are conducting a 4 week, 1 hour Lego Robotics program for the Middle School DIY Club. We decided for the first lesson, we would introduce the concept of Lego Robotics with the WeDo kits. Even before we turned on the computers, they were off and running. Once the software was installed, it was literally plug and play.
A note about software: if you do not have Apple laptops with CD/DVD drivers, it takes a bit of computer know-how to trick the mac into thinking the CD is there (our windows laptops were no problem!).
WeDo projects can be made in under an hour, unlike the Mindstorms Gyro robot I've spent about 6 hours building only to find out that I must have missed a step somewhere and need to take it all apart (there was lots of silent screaming). Not to mention, I've spent so much time building it I haven't even gotten to the coding part yet. It could take an entire semester to build the robot and program it. As I was struggling on the desk putting my Mindstorm robot together, one of the elementary school students came up to me and said,
"You know on YouTube there are a lot easier projects"
"Oh where were you a few hours ago?" I replied.
"I was in school of course"