what is wrong with Sequoia 15.0.1?

Anyone else experiencing issues with this MacOS update? my iMac (a few years old but still meets requirements for Sequoia) and MacbookAir which I bought this year (ie the one with the new chip) are both causing problems. The iMac is pretty much useless-

neither have successfully downloaded and installed the update - after hours of trying.

definitely not an internet connection issue or HD space issue. No error is coming up - they just get stuck at x minutes for hours.

😭