Di2 Cheat Sheets are here!

[Spinnekop]

I also ride in winter and frozen fringers and Shimano Di2 shifting is almost impossible. It is much better with 12speed as was with 11speed, as you can feel one button is more outwards, but when deeply frozen fingers, is still very hard to make the right shift.

You're not wrong. Same issue here w/ long fingered gloves regardless of finger temp.

I'm also looking for a solution that doesn't involve synchro shift, top buttons, etc.

Part of me regrets not getting new Red, but the Di2 shifts lovely front + rear.

Also in two minds about the new RED.
But after playing with one of my friend's bike this weekend I am happy with the Di2.
The new Red lever is VERY wide and flat. Don't know how I will feel about that over a long time. Also the breaks are not Shimano. Not bad. Just not Shimano.

[Agent041]

I also ride in winter and frozen fringers and Shimano Di2 shifting is almost impossible. It is much better with 12speed as was with 11speed, as you can feel one button is more outwards, but when deeply frozen fingers, is still very hard to make the right shift.

You're not wrong. Same issue here w/ long fingered gloves regardless of finger temp.

I'm also looking for a solution that doesn't involve synchro shift, top buttons, etc.

Part of me regrets not getting new Red, but the Di2 shifts lovely front + rear.

I now also upgraded my gravel bike with GRX Di2 12speed. I was thinking of cheaper 105 Di2 as mainly I ride on road, but went for the GRX, as it has upper button positions way better as Ultegra. So you can reach them with your thumb. But the button is so hard to press, it is practicly useless even in summer. And naturally in winter even more. Great groupset, but the hardness of the upper button is a big downside.