I love my T-Mobile edition Z3. I had one on pre-order and cancelled it when I saw reports of the camera being downright wonky. I turned my attention to the Nexus 6, but turned to the Note 4, deciding I'll wait for the dust to settle on supply issues and early bugs.
I played with a Note 4 for what seemed like a good half hour on two occasions in the store. I couldn't get passed the phablet thing. The Z3 is pretty damned big, but it's not in the obscene territory the Nexus or the Note 4 is.
The Note 4 camera is impressive, but it tends to over-sharpen everything. On some shots, it really looks out of place. It's harder to soften a over-sharpened photo and have it look natural.
I bought the Z3 knowing I'll get a new phone in another 6 months. Either a Z4, Nexus 6 or even a S6 if they tone down TouchWiz and improve fit and finish. (Galaxy Alpha looks great).
The camera is a surprise. I've been seeing some really bad images uploaded on the various Android forums, but I love it. The in camera post processing evens out the tones to what I do similarly on SLRs in Lightroom or Photoshop. And as far as detail, the data is there. If I want to crank up the sharpness, it will do it. Snapseed and VSCO Cam do rather well with the Z3's images.
I came from a 2013 Moto X. And the images were as good as it would get right out of the camera. There was no detail or dynamic range to play with. Evening out tones was impossible. Colors were wonky in low light or artificial lighting, and the processing would kill any detail. Daytime shots were nice and good enough most of the time.
The Z3's camera app is a little slow and not that well thought out. But there is plenty to play with. HDR is limited to 8MP, and not the 15MP or 20MP options.
You can get around that by using the Google Camera app.
Pros:
-Great aesthetics, fit and finish
-The best LCD screen around, kind of sick AMOLED.
-Fast
-Outstanding battery life. I tried killing it before the end of the day, but I can't.
-It's skinned, but Nova fixes most of that. Stuff Nova can't do like pull down menus and the dialer/contacts app are pretty minimal.
-Great image quality from the camera.
-It's features checks off all of the boxes, NFC, ANT, etc.
Cons:
-It's not pure Android.
-Updates will be there, but slower than HTC, Motorola, Samsung.
-Camera app needs a lot of work.