i played 2 games so far and in my first Rome had such a tech lead that i had no chanse to catch up.. and in my Current game Hiawatha is 8% above me.
Feels like the AIs are now more focused on teching.
The patch corrected a flaw by which the AI neglected/didn't prioritize enough its science buildings. That was harming massively the wider civs in the game that grew big but fell back in science, and with the warmongering penalties lost most other means to catch up (RAs, TR to foreign civs, etc.)
I've played on King since the patch (just moved back to Emperor again), and I find them much better in science indeed. You need now to be more careful about the wide civs, especially the ones that build tall first and circa the Renaissance begin to conquer with success and become wide. The Casimir AI is the best at that in my post patch games, especially if he starts on
my continent with a few neighbors . Mid game he swallows them up and transforms into a science runaway with a mighty army. Of course the human don't give him the warmongering penalties, so he ends up my main trade partner by default after eating up my friends, which isn't good. If on the other continent one or two AI have become strong too, he switches to culture or science, with success.
A side effect of the tweaks is that now that the AI doesn't neglect Universities the wider ones have tons of cities in which to build archeologists, which they do.
In my first patched game I installed the patch mid game only to see the huge but backward Casimir become both tech and culture leader. He had both a SV and a CV within reach, I was only able to stop him by winning diplo on the second session for WL. The warmonger penalties make it harder to control runaways like this aggressively.
Now I find it's better to take no chance and play the early King/prince games more with the science catch up strategies used on the higher levels, and eventually get ready to build or grab a few more cities (in peace deals, preferably, or by buying/marrying CS if you're Venice or Austria) mid-game if you find out the wide civs are catching up on your early tech lead.
Doing that gives enough of a tech lead and makes Prince/King pretty forgiving again by mid game or so. The few times the AI caught up again in Modern, I finally went wide/tall as I had the happiness and money for it (as Venice, so a mixed strategy of buying big CS and buying them all the science buildings immediately, and conquering my neighbor patiently, not taking cities but getting them in peace deals, warring with allies whenever I did, all this before I finally went for his capital late enough that it only gave me a minor penalty. I was able to avoid most grief, keep my DoFs and thus the RA opportunities. I was in the Information Era when the first AI reached Atomic, the others over 20% behind).