I'm seriously considering getting one, and I can already see how the MotoMods would work for me. One of my biggest concerns about this announcement was wireless charging, which Motorola has ignored for the last few flagships, and this is addressed with one of the battery packs which I'd probably get anyway. I could also imagine having two or three of those simple covers to swap out depending on my mood. Spec-wise, it ticks all my boxes. That speaker mod also seems like a nice alternative to a portable Bluetooth speaker.
I don't think the design is perfect but I immediately found it very attractive (as long as the front is black). The "moto" branding on the front is rather tacky and should be removed before production if they come to their senses, and the fingerprint sensor that isn't a button is a rather sloppy design choice. That said, I love the shape and simplicity of the frame and I think the camera design is gorgeous. It's like they've taken ownership of the Moto 360's initially-regrettable flat tire and turned it into a sort of design trademark.
Headphone jack is a non-issue since I use Bluetooth headphones.
There seems to be an unusually negative reaction to this phone and from what I observe a lot of it comes either out of Verizon-related frustration or from people who loved the Moto X and what it stood for. The X never really convinced me, so I'm not bothered by how much of a departure the Z is. And not being in the US makes this carrier business irrelevant to me.
One thing I'm concerned about and eager to see is the camera performance. I'm not interested in the Force (and not in the US anyway) so the fact that the Z has what is probably their second-best camera gives me pause.