I did a modest test of the maps where I live (in North America) and it worked exactly like Google Maps did.
I'm not saying there aren't problems with Apple Maps -- I don't live in Japan, for example, I don't rely much on public transit, and my city appears to be very well-mapped (and I've never used Street View on my iPhone). Just adding a data point that, for me, the whole GPS driving thing works exactly as it did before -- except that the maps are much more visually pleasing.
I'm very confident that six months from now this brouhaha will blow over, though I understand that users NOW who need the maps they had NOW are justifiably a little miffed at Apple for removing the Google Maps app. IMO Apple should have simply moved the Google Maps app to the last page (heh) but kept it around until they felt sure Apple Maps was as good or better, THEN deleted it. So bad move on Apple's part overall IMO.
Still, I think part of the "outrage" comes from people who are new to Apple. This company takes chances, and sometimes makes missteps or just plain fails. MOST of what it does works great out of the box, but if you're going to get on this train you should know that (like EVERY OTHER company out there), sometimes they step in it. This is the risk you take when you INNOVATE and take risks. I'm sure Apple was aware that Maps wasn't fully-baked, but figured it was good enough (and that third-party transit apps would fill in the gap) until it was. That was a mistake, evidently.
I remember when they revamped iMovie (and Final Cut Pro and a dozen other programs over the years). OH THE WAILING AND GNASHING OF TEETH. For six months. Then the updates arrived (or people just got used to it) and guess what ... now they love it.
I suspect Maps is like that. A year from now it will be your best friend.
As for the sales, I suspect Apple could have sold many, many more (judging from severe shortages where I am) if they'd been able to make more. Sharp's dropping the ball on screens probably hurt them. Looks like they'll easily sell a few mil more in the first week once the replenishing shipments arrive.