Numbers from Steam hardware survey show a bigger spike in Tahoe adoption in February than we see from Telemetry Deck. Tahoe went from 62.2% in January to 78.7% in February. ...There can be fluctuations, so take that with a grain of salt.
For reference, according to Steam hardware survey, Sequoia had 90.2% adoption at this point one year ago, and Sonoma had virtually 100% adoption at this point two years ago. So, despite the "spike", Tahoe is still lagging behind its immediate predecessors.
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I still haven't upgraded yet, but right now I am thinking that 26.5 (late May?) will be when I bite the bullet. I will still be keeping an eye on adoption and prevalent bug reports between now and then, though, and I might change my opinion...
Despite my complaints about the visual style, for me the issue holding me back is more around bugs/stability than the new design. The mid-cycle releases (March/April "X.4") tend to be more risky, as Apple tends to introduce their last batch of major changes at that time, before fully shifting focus to "fixes only", and "the next major macOS release" ahead of WWDC. Last year (15.4) we had them breaking Canon RAW photos in some apps, and the year before (14.4) was particularly disruptive with them breaking a number of Java apps, USB hubs, and printers.
If the betas for 26.4 are any indication, they are still mucking around with things; 26.4 beta 1 broke auto-mounting HFS+ volumes and 26.4 beta 2 has created networking breakage for people who have any network filters installed (Little Snitch, VPN apps, etc.). Both of these issues were fixed in the subsequent beta release. I hope that they get this in a stable spot before the final release of 26.4, but I still think that I myself will be waiting for one more after that.