After I updated to Cyan, here's what I found:
A. Welcomed features:
1. Action Centre/Quick Setting
2. Web video: ability to jump to specific time
3. Touch-sensitive button (Windows & Search) - no more accidental presses, if you press them long enough.
4. Internet Explorer : unlimited tabs allowed
5. Independent volume level
B. Regressed features:
1. Web video - the time seek bar is awfully small, and sometimes it shows only on landscape view
Also, you can see white page (only a fraction of a second, it's very quick) when switching from portrait to landscape view. Very unelegant.
2. Internet Explorer - no more tab counter
3. Internet Explorer - tab arrangement is dynamic AND confusing.
On WP 8.0, the tab is arranged by the order you open them
On WP 8.1, the tab is arranged by which one you currently view. As the result, I often close the wrong tab.
No longer you can use back button to view previous tab. If you use 'open in new tab', pressing back will close the current tab.
4. WiFi - no option to 'turn off WiFi if phone is locked'
5. Photo quality seems to be worse (noisier night time photo)
C. Bugs - happen on Cyan but never on WP 8.0
1. My 925 often freeze, maybe every two days. I need to reset it (Volume Down + Power button).
2. After I reset/restart my 925, sometimes the time and date will go erratic... it will be set to 22 May 2014. The same happens to the clock, it will be set to sometime at 9. I will need to set up the correct time and date.
3. Internet Explorer often, without notice, close the page you're viewing. Or, it will quit all of a sudden, back to the Start page.
4. Sometimes the phone speaker give a 'crack' sound. This happens when the speaker is inactive.
5. Web video - sometimes the phone produces no sound. This is no hardware issue, the same thing happens on my 520 with Preview for Developers. Definitely software issue.
D. Still missing features:
1. Internet Explorer - no way to distinguish which tab is active.
2. No cursor on phone dialler.
Having no cursor on the dialler means:
1. Inability to edit wrongly entered number
2. Inability to add international code at the beginning of a phone number
Conclusion:
I do not like WP8.1 / Cyan. :unhappy: