Yes, it is buggy. I tried it out on my way down to Corvallis yesterday and it insisted I needed to jog around the back of Barbur Foods to get onto I-5 south from Barbur Boulevard (even as I was entering I-5 it was still trying to re-route me). Then on the way back the turn-by-turn directions feature was not working and I could not reset the "current position" to my current position. Finally the traffic feature is minimal and pretty darn unhelpful and hard to see.
Unfortunately, once you upgrade to iOS6 you cannot recover Google Maps.
What is better about it than Google Maps? Well, when it worked the turn-by-turn directions were great, along with the 3D view. The maps are clearer and easier to read than Google as well. But I really miss Street View.
You have to think that if Steve Jobs were still around, this would have NEVER seen the light of day until it was perfect. Which is a really bad omen. Time to sell Apple stock?