Let's start with this - if you're an orthodox fan and believe books should be adapted sentence by sentence, it's simple - don't watch.
For those who don't know the books, I'll start by saying I've read most of Asimov's books. The Foundation cycle began to be written in the 1950s. After a long break, more books appeared in the 1980s. In this case, modernization seems not only justified but even necessary. Unless you like a strong retro vibe where the Galactic Empire is completely based on nuclear energy, which represents humanity's greatest achievement. Similarly, contemporary viewers will relate much better to Seldon as a consciousness transferred to a computer than to films recorded on tape by Seldon and watched (or ignored) by descendants. Moreover, it's worth adding that Asimov's saga is famous for internal inconsistencies. For example, initially Trantor is located in the center of the galaxy, as befits an empire's capital, later it's on the galaxy's arms where there's no dangerous radiation from the galaxy's center - Asimov repeatedly changed details in the novels, adapting them to the progress of knowledge.
The series has been extremely modernized; we can watch fantastic technologies and absolutely stunning shots. Which I mostly rate as a plus. A certain flaw of the series is its distinctly different character. The series is much more adventure-oriented, individualistic, and brutal (especially in the Season 3 finale there's quite a bit of senseless carnage), but it's also more mature. The Foundation saga, despite its political and social scope and, for the 1950s, often considerable courage, was nevertheless quite infantile.
The acting is good, the characters are very diverse. In my opinion, the best-written character is Demerzel (Laura Birn); for those who've read the books, she once bore the name Daneel, among others. It's an excellent development of Daneel's character, more realistic and deeper (though the way she holds her hands and the robes she wears are awful). The worst-written is the Mule (Pilou Asbaek). He's been exaggerated into a sadistic brute and in a sense split into two characters because Magnifico Giganticus (Tomas Lemarquis) is a second character in the series. And actually three characters, but I won't write what the third is. I had high hopes for the Mule, which the series didn't fulfill. Though for a change, the marriage of Bayta (Synnove Karlsen) and Toran (Cody Fern) Mallow, connected in some way to the Mule, was extremely skillfully modernized. Modernization is one of the series' greatest assets. But even in this regard, there are slip-ups. The imperial weapon in the form of a black hole launcher is great, but unfortunately the creators didn't think or ignored that a black hole wouldn't stop after swallowing a planet; it would grow and fly further, perhaps in a different direction. Distance shouldn't be any problem for this weapon (so why not attack the Mule?). To put it bluntly, here the creators overdid it in a way typical of Nolan's pseudoscientific films. A shame.
It's somewhat difficult to rate this series unequivocally. It's certainly an ambitious attempt to modernize Foundation. At times it departs very strongly from the original, but usually in a good direction. It's definitely more mature but often unnecessarily brutal. Sometimes there are slip-ups, but rarely. I think 8 stars is a good rating.
