I really wanted to love the Nokia 6.1. Because it's part of the Android One program that ensures timely OS and security updates and features a clean Google Android experience, it's basically like a midrange (much less expensive) version of the Google Pixel. It also ticked my other boxes: unlocked (not tied to a specific carrier), rear-mounted fingerprint sensor, NFC chip for Google Pay, nice full HD screen, reasonably fast processor, premium-looking high-quality build, etc. I knew the phone was bigger than I wanted (even bigger than my prior phone, a Nexus 5X) but phones keep getting bigger and there wasn't anything smaller that offered all the features this phone had, at least at anywhere near its price, so I bought it.
Unfortunately, after more than a month of use, there are three flaws this phone has that keep me from being fully happy with it. First, it's just not comfortable to hold for any length of time due to its width and its boxy design with somewhat sharp metal edges. At 75.8 mm wide, it's only 3.2 mm wider than my old Nexus 5X but that's enough to make a difference in my hands (which are, I'd say, average size for a man). And though the precision-engineered metal chassis of this phone looks fabulous, it simply doesn't feel as good to hold as the curved soft-touch plastic of the old Nexus 5X. (I don't use phone cases, BTW.)
Second, the fingerprint sensor on the back of the Nokia 6.1 is simply too small. It doesn't look THAT much smaller than the circular sensor on the back of the Nexus 5X but it's enough smaller that I CONSTANTLY get partial scans and have to try multiple times to hit the sensor just right in order to unlock the phone. Think how many times a day you unlock your phone. It should be really easy to do but, with this phone, it's a real hassle. I thought I would get better at this over time but I haven't. (I've read other reviewers complain about this too, so it's not just me.) A lot of times now, I just turn the phone over when I pick it up so that I can see the sensor on the back and aim for it with my finger and therefore unlock the phone on the first try. Also, the sensor is awkwardly positioned too low down on the phone. It's not where the tip of your index finger would normally rest when you pick up the phone. Poor design choices all the way around here. Grrrr.
Lastly, the camera. OK, I knew going in, from multiple reviews I'd read, that the camera was universally known as the weak point of this phone. And yet I've still been disappointed with it. Shots in bright daylight look nice, although fine detail is still not quite as sharp as I'd like to see. But it's when light is anything other than ideal that things go wobbly. Indoor shots during the daytime look sub-par and slightly muddy, with more shadowy areas especially looking noisy. Forget about truly low-light evening/nighttime photos (which I knew about before buying). And even with HDR turned on, dynamic range is just so-so, even outdoors in the daytime. Plus, the camera app can be dodgy. I needed to quickly get a shot recently but repeatedly clicking the shutter button did nothing. I had to close the app and re-open it to get it to work. And then Nokia updated the camera app last week to add some features, etc. And now HDR doesn't work. If I take a photo with HDR turned on, it gets stuck forever "processing" the photo after taking it. I'm sure a future software update will fix this bug but this does NOT inspire confidence in Nokia. If the camera had merely been as good as the one in my old Nexus 5X -- a mid-range phone from 3 YEARS AGO! -- I would have been happy. But alas, the camera in the Nokia 6.1 is definitely a step down from it.
Apart from those issues, though, the phone is quite good. Call quality is good. The phone has been stable and generally very fluid and responsive. However, I have seen some occasional laggy scrolling, usually just after waking the phone in the morning. Still though, nothing major. (But note that I haven't tried playing any graphically demanding games.) Nokia followed through with the September Android security update just a few days before the end of the month. (An upgrade to Android Pie is supposed to be coming later this fall.) As Nokia says, this phone is "built like a tank" so you don't have to use a case. It's sturdy but also feels heavy in your hand or pocket.
Considering the cost of this phone, the Nokia 6.1 still offers a lot. Trade-offs are unavoidable in any phone costing less than $500. The question is whether or not the specific positives of a given phone outweigh the negatives vs. other phones you might consider. For about the same price, I'm pretty sure I'd be happier overall with the Moto G6. It feels much better in my hand (at 3.5 mm narrower, with a curved glass back), has a front-mounted fingerprint sensor, and (based on lots of head-to-head comparisons around the web) appears to have an overall better rear camera than the Nokia 6.1 -- better dynamic range and better performance in medium and low light. Plus it has a more attractive 18:9 shaped screen. No, the build/design doesn't look as distinctive or premium. No, it doesn't have NFC to support Google Pay. And no, it doesn't get the sort of updates that the Nokia gets as an Android One phone. (The Moto G6 tends to only get quarterly, not monthly, security updates. Motorola has confirmed that it will get an upgrade to Android 9.0 Pie but that could be next year while Nokia has said the 6.1 will get it this fall. Plus, the 6.1 will also get upgraded to Android 10 Q in 2019 while that's very unlikely for the Moto G6.) But having played with an unlocked Moto G6 at Best Buy, I can say it doesn't have the flaws that bug me about the Nokia 6.1, plus it feels equally fluid and fast, has lean nearly-stock Google Android, and also supports all 4 major US cellular networks and even Google's Project Fi. Meanwhile, the Nokia 6.1 only supports the T-Mobile and AT&T networks.
The Nokia 6.1 is the best available option for some people but, in the end, it wasn't for me. I've decided to return it and get a Moto G6 instead.