I’m personally reading it, and it’s excellent.
It presents the main points of Kant’s philosophy,
the three well-known Critiques, and his views on history, education, and religion.
That said, I’d recommend the Open University book “A Study of Kant’s Introductions,” because Bergman’s language is a bit dated, whereas the wording in the Open University book is clearer.

Thank you very much.
At the end of Chazon Ish’s Letters, vol. 2, it is brought that it was written in the book, “Philosophy until Kant was only verbal toil,” and the Chazon Ish added in the margin, “including him as well.”
What do you think about this dismissiveness?

I wasn’t familiar with that. I’m not sure the Chazon Ish even knew or understood Kant. I certainly don’t agree.

Rabbi HaNazir related that he explained Kant’s thought to Rabbi Kook. Rabbi HaNazir said that although Rabbi Kook had not studied Kant in depth, his understanding penetrated to the roots of his doctrine and he offered a critique of it.
So perhaps the same was true of the Chazon Ish: he read a little (maybe even second- or third-hand) and understood the general direction.