Like others, I think I'd prefer the Model 26, which has a good reputation. But, consider this: a lot of people in the Glockiverse have been clamoring for a single-stack nine for a long time. Glock has given them what they wanted, and that's what business is about.
Definitely interested in one. Besides being a .380, the G42 was just a wee bit too small for me, as is the Karh PM/CM9. Sounds like the size of the G43 may be just right.
There's also not enough size difference between the Shield and my 3913 to make the switch. I won't pay north of $500 for a 43, but folks are already ordering them for about for around $400, and if the Blue Label price is $385 as has been reported, I'm in for one.