My issues so far (4K Resolution; Windows 11):

Tab Button Size in Tab Islands
The grouped tabs/tabs in a tab island now have a smaller "hitbox"/area to click on than the other tabs. So if I quickly move my mouse cursor all the way up to the border of the screen and click (as it worked before), nothing happens. I'm so used to doing this in my workflow and now it's really annoying. My solution so far was deactivating/not using the tab island feature. I like the idea of that feature, but in its current state it drives my crazy.

Weird border around the browser window
As another user has posted, the whole browser window now has a border, which imo is not necessary and looks not great on some websites depending on its colour.

Speed Dial icons can look ugly
Maybe it's just me, but I don't like how the Speed Dial looks now. Fields with small icons depending on the website? Some icons are not made for this and are stretched (I guess the fault of the website), other icons don't look great in general, etc. It imo looks just terrible. I have also some dials to different branches of a bigger website "conglomerate" and they all have the same icon and colour. As a result the dial fields all look the same and my first visual impression opening the speed dial page leaves me searching for a moment. How it was done in the old version or in Opera GX works much better for me.

My issues so far (4K Resolution; Windows 11):

Tab Button Size in Tab Islands
The grouped tabs/tabs in a tab island now have a smaller "hitbox"/area to click on than the other tabs. So if I quickly move my mouse cursor all the way up to the border of the screen and click (as it worked before), nothing happens. I'm so used to doing this in my workflow and now it's really annoying. My solution so far was deactivating/not using the tab island feature. I like the idea of that feature, but in its current state it drives my crazy.

Weird border around the browser window
As another user has posted, the whole browser window now has a border, which imo is not necessary and looks not great on some websites depending on its colour.

Speed Dial icons can look ugly
Maybe it's just me, but I don't like how the Speed Dial looks now. Fields with small icons depending on the website? Some icons are not made for this and are stretched (I guess the fault of the website), other icons don't look great in general, etc. It imo looks just terrible. I have also some dials to different branches of a bigger website "conglomerate" and they all have the same icon and colour. As a result the dial fields all look the same and my first visual impression opening the speed dial page leaves me searching for a moment. How it was done in the old version or in Opera GX works much better for me.