On various concerns that have been expressed:
1) I noted Minor Actions specifically before combat began. I asked everyone to find all the Minor and Move actions they had. 2 players had 2 minor actions, 2 more had 1. Most were healing or defense related. There was also dragon breath.
I told them that Minor Actions were utility actions taken during combat, and the exception was the Dragon Breath, because it was as simple as breathing for a Dragonborn. They got it. No one had any problems with the concept, and no one had any problems figuring out if they wanted to use them (I had called out the Minor Actions as "special" in their minds, and they tracked them as something different from a Standard Action).
2) I designed the classes for the playtest. What, did you think those were 5 of the most complex classes I could find? The optimal action for the Ranger, most of the time, was Twin Strike. Sometimes Twin Strike and Action Point for MORE Twin Strike. Yeah, it's that good. You EASE people into this, you don't pick the most complex class you can find and dump people in it (it's no surprise the experienced person got the CA Rogue which I told people was the most complex class). You let them see someone playing a complex class, and you show them simpler classes. People will split the difference.
3) This was WAY more complex than anything done in D&D encounters. This is for a reason. I wanted to show them what 4E enables for epic combat, and epic combat is not possible without risk. I told them a TPK was probably around 40%-60% likely. Seeing them play, they came awfully close sometimes. The rogue and ranger were both sub-10 HP at the same time at one point, and a Healing Word charge had already been used.
Speaking of which, something that was legit confusing. The Cleric said "I used healing word, I can't use it again." Had to explain Healing Word being a "special" encounter power. He read it, got it, and we were good, but the Red Coding tricked him (Oh look, that color coding is GENIUS).
The use of Flaming Sphere wasn't immediately obvious to the Wizard. Once things started burning, he got it pretty quick. The Action tradeoff was super-intuitive (use a move to make a move with the sphere).
If you have someone new to the game in general, give them a Bow Ranger. They'll feel effective (mostly because they ARE effective) and their action tree is super easy. "Doing something? No? Twin Strike." That being said, the guy playing him actually grasped Hunter's Quarry nearly immediately (he was the one with some experience) and started using it effectively.
The Fighter legit loved playing the class. As I said, he mostly tanked by being near the slow moving zombies, although Cleave was super effective at cutting them apart, and the Zombies mostly attacked the nearest thing, which helped him (they're ZOMBIES! What, complex tactics? Nah).
It did drag some, but they were having a good deal of fun, and by the end even other new players were conspiring with each other to figure out what they could do. It helped everyone had everyone elses character sheets, and were collectively reading them. It slowed the play down, but it also made it 10x easier, and helped THEM to learn how to read the sheet (as opposed to them asking me to read their sheet).
Oh yeah, and as I said encounter complexity makes encounters look like cheese, no offense