The battery drain HAS definitely been worse on both my Apple Watch 9 and my iPhone 15PM but that's expected. It's not the biggest disaster of a x.0 DB1 I've tried, but it's pretty rough. I came across an annoying bug where sometimes the send button on Messages stops working until an app restart.
I also found the general sluggishness with the UI subsided after the first couple of hours of indexing BUT it gradually starts to get laggier again as it stays on. Device restart helps clear it up again.
Even if you are eager for this, just wait for a couple of beta versions first. You'll probably be better off