I've noticed this over the past few weeks.
Adlinks that used to be configured to match my page's look now have borders and text-alignment irregularities.
I thought possibily this had to do with opting in for AdSense "automatic experiments."

I keep waiting for a report or suggestion about how their testing has turned out but so far none has come.

I serve enough pages that I would have thought a large enough sample size would have been created in just a very few number of days.

Another new "lool", brackets around a section along with a number...

ie: (#1 keyword) (#2 keyword) (#3 keyword) (#4 keyword)

...but the numbers are circled with a colored background while the rest of the text is normal link color. CTR is all over the place. Google is running A/B tests at my expense right now, is there any way to stop this? It's been over a week now.

All of the different looks appear badly coded because the keyword styles bleed above or below the area they have available. ie: the top or bottom of the new button styles isn't visible, it's outside the div allocated for the link.

I've always seen a flux in presentation.