A few things that I miss between the Z1 vs the Lumia 635:
- The Lumia 635 has phenomenal battery life. It's a weaker phone with a smaller screen, so I wasn't tempted to use it as much, but with the Xperia Z1, I turned on all the stamina mode features of the Z1 this time around, and have to get into the habit of keeping the phone charged the whole time. The day I didn't do that, battery life was abysmal.
- The smaller Lumia 635 and the fact that it's cheaper meant that the fitness tracking feature was actually useful. I could stick it in any pocket, and didn't really care if I was going to sit on it. There's a lot to be said for having a phone so cheap that I could buy 6 of it for the price of the Z1. The compactness can be solved by buying a compact Z series phone, but you can't solve for cheapness any other way than by spending less.
- That nice big screen is really sweet. When using it to shop on Amazon, or use Feedly, I never felt cramped or constrained.
- Apps. It's funny how Outlook is much better on Android than on Windows Phone. This is because Microsoft bought Accompli, but it's still nice. Similarly, I had to pay for Phonly (a view into Feedly) but Feedly on Android was free. People frequently say that having a forked Android store in the form of the Amazon App store hurts the Android ecosystem, but I disagree. Having 2 stores to shop from creates competition, which means that overall prices are lower for apps, and Amazon frequently gives me discounts or free coins to buy apps with. What this means is that apps I might have had to pay for on Windows such as Plex are essentially free on Android. Even better, because the Amazon appstore is not tied to a Google account the way the Google Play app store is, my wife gets those apps for free too!
- That camera on the Z1 is just amazing for a smart phone camera. Enough said. As a matter of fact, together with the IP58 waterproofing rating that's the reason to get a Z series smartphone.
- Waterproofing: lots of people claim that they don't see this as a key feature. The first time you rinse off the phone casually to get rid of fingerprints, etc., everyone else in the room goes, woah, you can do that?
- Power. Smartphone processors simply haven't been improving as rapidly over the last few years, so the Z1 is still within striking distance of current flagship phone performance. This is no big deal for typical reading e-mail, checking RSS feed, etc., as the 635 shows, but for photo editing and processing videos, it's nice to be able to do this without having to resort to a desktop or a laptop.