Tactical Themes You Struggle With

I'm just wondering what others' experiences are on this front. For the past two and a half months or so, I've basically put all the books away and spent the vast majority of my chess-time doing tactical exercises. Tens of thousands of tactical exercises. My improvement has been dramatic, so let me recommend the method. Do tactical exercises until your eyes bleed.

But in the course of this work, I've noticed that certain tactical themes trip me up. At first, I couldn't spot pins. Then I got to where I could. I don't really miss pins anymore.

Now my problem involves exchanging my queen. I have a tendency to overlook the possibility of gaining material by exchanging queens (so, you gain a minor piece or rook and exchange queens). My instinct is to keep my queen and forego the material. Which is wrong, I know. Now, I don't have this problem when I see that I'll be able to promote a pawn as a consequence of the exchange. So the problem, obviously, is my overvaluation of the queen.

Now, I suppose I'll get over this little tactical problem as I continue grinding through the exercises (esp. since I recognize the problem, even if I'm slow to correct it). But I'm wondering what other people's experiences have been with tactical themes that trip them up.