I have been using Windows Phone smartphone with 8.1 version on board and 512 MB of RAM. In my opinion, the mos frustrating thing was crashing web browser, i.e. Internet Explorer. Therefore, I prefer to use Opera Mini and this is my favourite web browsing application for all mobile devices. Mainly thanks to great data saving feature.
Unfortunately, I have very sad news for all people who use smartphones with Windows operating system. Windows Phone version of Opera browser will not get any new feature in the near future. They have tried to port iOS version using Microsoft’s bridge tools, but it turned out that it is not so easy.
In short: no major updates are planned for the next few months. This is, of course, not set in stone, and we're hoping to review the platform later this year. But, right now, the small team who were working on the Windows Phone app are now dedicating their time to our other apps on iOS or Android. Having said that, we will continue to make sure the browser on Windows Phone is still secure to use. The developers are also keeping an eye on bugs to fix major annoyances as they can (so keep your bug reports coming in!).