Is windows even worse every day passing?
Just makeup in each version+...

(Opera also has its incomprehensible things)

Times are changing, and Edge may look better aesthetically than Opera, Chrome and Firefox but it doesn't compete when it comes to and features and more importantly customisation which is why I believe that users should have a choice about how their browser looks and feels.

I prefer to avoid the top space in tabs, easly to switch between tabs.

You can use Opera maximized.

I could, but using Opera maximized on anything above a 1080p resolution is completely wasted, most websites don't utilise the space. This forum is a good example; the content width is only 900 pixels, why would I maximise my browser when 1660 pixels could be used for other windows? (I use 2560x1400 resolution btw). This is a problem that only gets worse the higher your resolution is.

As I said in my original post, I tile my windows to maximise the effective space. I'll have Opera snapped to the right of the screen and on the left I'll have a code editor, a terminal window and sometimes Spotify. When I tile like this often using Windows Key + Directional Arrows, then the wasted space above the tabs in my browser are really noticeable.

I prefer to avoid the top space in tabs, easly to switch between tabs.

You can use Opera maximized.

:doh:
You are talking about "restore" :s :whistle: :rolleyes:

Hummm...
Wait! Rereading is talking about title the window... :sherlock:

Even happens with Opera Mail too

Then I prefer to avoid the top space in tabs, easly to switch between tabs.

Didn't realized but it's true, that space isn't comfortable.

I prefer to avoid the top space in tabs, easly to switch between tabs.

You can use Opera maximized.

I prefer to avoid the top space in tabs, easly to switch between tabs.

Another valid reason, I often miss-click the wasted space when attempting to switch tabs.

There is still always a space between New Tab and Tab Menu buttons, try it yourself
What is not convenient as the space on the top.

I prefer to avoid the top space in tabs, easly to switch between tabs.

There is still always a space between New Tab and Tab Menu buttons, try it yourself

What is not convenient as the space on the top.

Even without the spacing above the tabs, there is spacing between the "New Tab" button and the "Tab Menu" button that I could use if I wanted to drag my window

What if you have lots of tabs opened?

There is still always a space between New Tab and Tab Menu buttons, try it yourself.

Example: http://imgur.com/a/ZGH9U

Even without the spacing above the tabs, there is spacing between the "New Tab" button and the "Tab Menu" button that I could use if I wanted to drag my window

What if you have lots of tabs opened?

This is achievable even in your younger brother "Vivaldi" using simple CSS (#tabs-container.top{padding-top:0px !important;}), I understand the technology is different but heck what a nice feature!

Are there any browser options or flags I can set to modify the spacing behaviour?

I know Leo said no but there actually is an option, but it's not enabled by default. However, I also don't think it's an option you're looking for. The option is: "Disable tab bar's top spacing when browser window is maximized", is it possible that this option got turned on somehow?

By default there's a very small strip left on top of the tabs (when maximized).

So to reach this setting: go to the Opera settings (Alt-P), enable the "Show advanced settings" option at the bottom of the menu. Then click the browser section and find the 'User Interface' section below. There the option I mentioned should appear.

Are there any browser options or flags I can set to modify the spacing behaviour?

Nope.

If I maximise the Opera window then the spacing goes away, but I don't understand why this isn't the default behaviour as the spacing is wasteful and really unattractive

The space is there so that you can drag the window.