I'd say it was pretty successful. We played the first game set, then a full random set out of the Base game.
The first game set ends up being really nice. It's pretty easy to explain, because most of the cards are straightforward, and the only things I needed to explain were the 1 action limit, 1 buy limit, and what gaining/trashing meant. They knew going into it that I had played a lot before, but since it was a 3 player game I didn't bother holding back, and I basically played the first game engine. It wasn't optimal, I made some building mistakes and skipped Militia because I didn't want to make it too painful, but 3 player is a nice dynamic for learning - I can have fun building up the engine, and the other 2 compete against each other and get their minds blown by my Village + Smithy + Remodel engine that's getting $13+ a turn. Then after the game I got to explain how my Remodel open let me change Estate into Village/Smithy early, how my actions let me shuffle cards into my deck faster, etc.
The second game ended up being a nice random set, because it included Village, Smithy, Throne Room, and also Witch, Bureaucrat, Gardens, with no trashing besides Remodel. So, after that engine game I got to show off a slower Bureaucrat + Witch + Gardens based deck that beat the engines both of the other players tried to build, which was a nice way to show that different approaches are better on different boards.
I'd definitely recommend teaching in a 3+ player game first, I didn't appreciate how multiple players lets you have tiers of competition until now. For the interested, our 2nd board was Moat, Chancellor, Village, Throne Room, Bureaucrat, Gardens, Smithy, Remodel, Library, Witch
(Note: in 2 player, I actually wouldn't be surprised if an engine gaining VP through Remodel could beat out the Gardens deck. It's definitely an uphill battle, but Throne Room puts in a lot of work here.)