Being a Vine reviewer puts me in a strange position relative to most phone users. I keep getting offered Sony phones, because I've reviewed them in the past. I have now reviewed the XA1, XZ1, XZ2, and XZ2 Premium. So I have a very fine grained perspective when it comes to the XZ3, and will approach this from the aspect of "which Sony phone should you choose?"*Why Sony?*First, I suppose, is the question of "Why a Sony Phone?" Well, the answer to my mind is an emphasis on entertainment, with excellent screens and front-facing stereo speakers. Second is camera, with an emphasis on high detail, high-megapixel photos. Third is general build quality - Sony makes beautiful hardware. Now, of course, Apple and Samsung also do these three things pretty well, too. They take differing approaches to camera and A/V quality, but I do think these three companies are within spitting distance of each other.*Sony’s 2018 Lineup*OK, Now, I'm going to compare the three most recent Sony models - the XZ2, XZ2 Premium, and XZ3. I don't know what Sony execs are smoking over there in Tokyo, but they have decided to release these models within 6 months of each other - from April through October 2018, respectively. So new stock is still available for all three. Why they chose to cannibalize themselves this way is beyond me. I can't imagine an XZ2 buyer being very happy with Sony releasing the XZ3 a bit less than 6 months after they plunked down for their current phone.All three phones share Sony's new "Ambient Flow" design language. This means they are round, slippery, shiny glass sandwich phones that have reduced bezels compared to their predecessors and a fingerprint sensor in the center of the rear of the phone body. All three share the "Motion Eye" camera sensor that excels at 960fps slow motion filming, 4K HDR video, and capturing bursts of moving still shots while staying in focus. All three utilize the Snapdragon 845 system-on-a-chip with Adreno 630 graphics. So they are all very capable 2018 Android flagships.The differences: The XZ2 has 4gb of RAM on board. It has an 18:9 IPS LCD display with a resolution of 1080x2160. The XZ2 Premium has 6gb of RAM, a 16:9 4K IPS LCD screen at 3840x2160, and a second monochrome camera module for improved low light performance. The XZ3 kind of splits the difference between the two. It has 4gb of RAM, the same camera module as the XZ2, but upgrades the 18:9 screen to a 6 inch HDR OLED display with a resolution of 1440x1880. Price wise, these models are going for 700, 1000, and 900 respectively at present.So the $200 difference between the XZ2 and XZ3 all comes down to the screen. And I will say, it is an absolutely beautiful screen. The blacks are as close to zero as they eye can see, and the brightness for HDR video is spectacular. It also has the trendy curved side edges that you might like on the Samsung Galaxy line. But otherwise, the XZ3 is functionally identical to the XZ2. It performs the same, gets basically the same 1-day battery life (5-6 hours of screen on time), and takes identical pictures. I would say the price premium is only justified if you really prize the display and watch a lot of high quality video.The XZ2 Premium is a bit of a different beast. It does perform basically identically on Android tasks, given the same internals. The 6gb of RAM seem to be dedicated to the camera, which is the big differentiator. Adding the second low-light module to the camera does improve low light performance over the XZ2 and XZ3. It’s not night and day (so to speak) but the differences are clearly there upon close inspection. There is more detail and less noise on the XZ2 Premium’s low light photos. Its screen is the highest resolution of the bunch, and it performs well with HDR video – though the XZ3 probably beats it with its deeper native contrast ratio. Now, is this worth a $300 price premium over the XZ2? Personally, I don’t think so. Given the choice of which one to use for free, I’ll take the XZ2 Premium. But if I were doing the math on my own budget, the XZ2 would be extremely tempting.*XZ3 Specific notes*The XZ3 does also add a few new features, almost all of which are superfluous. “Side Sense” brings up a shortcut menu when you double tap the curved edges of the screen. It is prone to misfires, though, so is more of an annoyance than anything. The phone also recognizes when you pull it out of your pocket and orient it in landscape, and pulls up the camera. But since you still have to tap the screen to initiate the camera, it really offers no benefit over the (wonderful) dedicated shutter button.The XZ3 is probably the prettiest of the three phones, and is also the lightest. If you’re into comparing phones with your friends, it is likely the one which will get the most “oohs and aahs” next to a Galaxy S9 or iPhone Xs.A case is an absolute necessity, since the phone is so thin, svelte, and slippery. I almost dropped it several times before nestling it into its excellent Ringke Fusion X case.*Conclusion*People who want to buy a Sony phone have been put in a hard spot by… Sony. It has released three similar flagship phones within 6 months. All three of the phones perform basically identically when it comes to speed. The XZ3 has the best screen. The XZ2 Premium has the best camera. Which of these three areas of performance you value most is how you should make your decision if a Sony phone is in your future. I frankly think the XZ2 will offer the best bang-for-buck for most users. It is also the model that is now best situated to compete with phones like the OnePlus 6T on price. Only those who seriously prioritize display or camera should consider the “step-up” models, which come at a significant price premium.Photos:1. XZ2 Premium cat in very low light2. XZ3 cat in very low light3. "Side Sense" menu in action4. HDR 4K video in action5. City scene at dusk6. XZ3 Running Square Home 2 launcher7. XZ2 Premium still life in good light8. XZ3 Still life in good lightPlease see the comments for a link to higher res images.