I counted in both games I played last night, but I usually don't. But I have a hard time keeping track of what I counted in my head, because I'm not used to it. So each time I counted I had to start over from the beginning, e.g. "Was the big area on the bottom 35 points or 45 points?" Unfortunately, I lost one of the games because I got time short and felt rushed; the score was close enough that I might have won if I wasn't time pressured.
My estimating is not very good and my counting is not much better, and it's slow. Which is why I'm trying to do it more.

But at the speed I usually play (automatch medium), it seems like it's only borderline worth it.
The other day I played a game and I thought I was behind by about 10, maybe less, so I figured it was worth playing through endgame. I lost by more than 30 and was embarrassed for not resigning. So I resolved to learn to count to avoid that kind of situation.