I'll admit it, originally I was an Intro-denier. I couldn't see the point, and thought it would really eat into the day with all the extra course building and walking. Novice was short and simple enough and it was a handler training issue if they couldn't figure out how to take what successes they could get on the course even if they didn't get every single obstacle completed.
And then I watched it. Well, technically I judged it, but I do tend to watch at the same time oddly enough. :-)
Experienced handlers know that part above about taking and celebrating those successes you can, because every single one of us has applied our own heads to that brick wall with our first dogs, have burned those circles around obstacles forcing our green dogs to do EVERY SINGLE OBSTACLE come hell or high water, certain that's what our dogs needed to understand, right up to the point that both we and the dog began to reconsider whether this was actually fun. If you didn't have a trainer to ease you and the dog away from that wall, well it took a lot longer to get that one figured out.
That's why Intro is brilliant, imho. Half the obstacles means you and your dog don't have time to get into that deadly frustration destructive feedback loop, even if you do get stuck trying to burn those circles. After a year of watching it, I have yet to see a dog and handler leave frustrated. I've seen fearful or bashful or quick-to-disconnect dogs forget to be that because it was over before they thought about it, and they've all left *happy* and improved drastically over a weekend.
I am a believer, a convert, a proponent, heck, an evangelist! I'm not going to say I think it should be a mandatory level completed before entering Novice - some folks with available trainers may be ready to shift up - but I will say that this is a new trick that every old dog (yes, I'm even looking at us curmudgeonly elite handlers) could get fantastic value from, really a pure happiness class.