Wow. Just saw this over Yom Tov. *[Rav Avigdor Miller on Tefillah][1]*, just published (2021), by R' Yaakov Astor, quotes from his shiurim. [He says in the introduction that some of the quotes were lightly edited. I couldn't tell which shiur it came from.] Anyhow, p. 127:  

> Question: In P'sukei D'zimrah there are so many selections from
> Tehilim, and the Rav has told us that every word is a gem and an
> opportunity for perfection of the mind. But can one really concentrate
> on so many verses and so many different thoughts?   

> Answer: Certainly
> not. And therefore, you shouldn't even try to to say everything. Just
> to rattle off words and not gain any da'as, is worthless. It's not
> completely worthless, but it's just about worthless.   
Instead, take
> your time. "Tov ma'at tachanunum b'kavanah m'harbeh b'li kavanah -
> Better to daven a small amount with concentration, than to daven a lot
> without concentration. Say a little, but think about what you're
> saying. Study the words and understand what you're saying. That's the
> real achievement in davening.   
Now, of course, if you have a great
> deal of time, you can start davingin three hours before the tzibbur,
> and you'll be able to do justice to a good part of the P'sukei
> D'zimrah. But whatever it is, you should spend time using your head in
> davening, not just your lips.

"You shouldn't even try to say everything."


  [1]: https://www.amazon.com/Avigdor-Miller-Tefillah-Rabbi-Yaakov/dp/1607633442/ref=sr_1_8?dchild=1&keywords=avigdor%20miller&qid=1632986678&sr=8-8