Software & Battery Life
I'm not going to spend a huge amount of time on the software section, and that's because Windows Phone is essentially the same on every device. The Lumia 735 I was sent to review was loaded with Windows Phone 8.1 Update (build 8.10.14157.200), which contains a few minor upgrades over the version I used on the Lumia 930.
Of these updates, the improvements to Internet Explorer 11's web compatibility was the most useful and noticeable. Websites no longer deliver awful dumbphone-optimized mobile sites to IE11 on Windows Phone; instead you get the same version as you would on Chrome for Android. This means you get all the benefits of responsive designs on major websites, especially those who never bothered to test on Windows Phone.
Other notable updates include app folders on the Start screen, improved live tiles for some stock applications, the Apps Corner for sandboxing apps for other users, and widened location support for Cortana. Unfortunately, despite being from a supported country (Australia) and having the correct locale settings, Cortana still refuses to work for me, saying that it can't speak my language. How frustrating.
Aside from these changes, all the same strengths and weaknesses of Windows Phone are present. The selection of apps in the Windows Phone Store is still a major weak point for the platform, and although most of the apps that you would want are available either as a first- or third-party version, the quality simply isn't as good as iOS or Android. Sure, there are some gems in there if you look hard enough, but the majority of the apps are disappointing in terms of quality.
That said the actual features baked in to Windows Phone are very solid, from an excellent Start screen and a cohesive design across apps to enterprise features and an information-rich lock screen. The settings screen is still awful in terms of organization of options, but if you dive in there you'll find a fair bit of control over how your device operates. The recent inclusion of the Action Center also improves on a solid notification foundation.
Inside the Lumia 735 you'll find an 8.4 Wh (2,220 mAh at 3.8 V) removable lithium-ion battery, which is a tad small compared to other devices. The Sony Xperia Z3 Compact, for example, is smaller than the Lumia 735 physically but packs in a 9.88 Wh battery. The reduced capacity of the 735 is likely (in part) due to the removable battery, which requires more plastic housing than an internal battery and therefore has less space for the actual cell.
During my general usage of the Lumia 735 I found it to have good, but not outstanding battery life. The handset appears to suffer most from web browsing on 4G LTE networks (which won't be as much of an issue for Lumia 730 owners), but on Wi-Fi the 735 performs well. Turning off NFC and high sensitivity touch mode, both of which are enabled by default, also helps to improve battery life straight away.