I placed an order for this new lens when they were announced last December or so. I received it a month ago and have had a chance to use it some. Here are my initial impressions:
First, my main interest was in a compact alternative to the SEL1855. I find that lens just a bit too large and heavy to conveniently carry around while hiking or backpacking. I use a Peak Design Capture clip on my shoulder strap to carry the camera with the bigger lens; but that leaves the camera a bit exposed.
Normally, I use the wide-angle SEL16F28 lens, and carry the camera in the Sony LCM-EMA/B. I find that to be a great carry case: convenient, compact, lightweight, and sturdy. Goes on shoulder strap or belt clip.
So the SELP1650 seemed to offer the versatility of the 3x zoom 18-55. As it happens, it barely fits in my case. I added a cheapo circular polarizing filter, which adds a bit to the length, and still it fits. The case does press on the lens a bit (I can see an indentation in the padding inside).
The lens seems to work well. I'm not a pixel-peeper so I can't really comment on softness in the corners or such. I get 3x zoom, plus keep the slightly wider 16mm versus the 18mm. I think I'll start carrying this lens as my default.
A few comments on the lens itself. The focus ring also serves as a zoom adjust ring (not sure what the technical term for this is). That takes a bit of getting used to. I often use the manual-focus adjust, and if I don't get the shutter button halfway down, then my attempts at manual focus zooms in and out, instead. Sometimes, even with the shutter button halfway down, if the camera doesn't lock focus, then manual focusing doesn't work and the lens zooms in/out.
The other thing I've noticed is that the smaller lens cap (40.5mm instead of 49mm) seems to not be as secure. It's popped off a few times while slipping the camera back into the case. One time I lost it and had to back-track to where I took my last picture to pick it up off the ground. Maybe that's due to the filter, though.
All-in-all, I like this lens and will definitely use it.