Thanks -- correct me if I'm wrong but I thought lit-element is the bit that does components and lit-html (I think the naming is pretty bad here) is just the rendering bit, is that right?
I was already on the fence about what to try next, and Svelte is at the top of the list if I have any problems with lit-element... lit-element just seems a bit lighter and more standards-positive so I wanted to give it a go.
These days though, I'm basically not considering investing in any libraries/frameworks that don't offer SSR with competent hydration. IMO it's the closest we get to the holy grail in frontend -- separation from the backend (which I argue is a benefit), and the SEO-friendliness, nojs-compatability, and speed of server side rendering.
lit-element doesn't have a good SSR story just yet (it's experimental[0]), and Svelte has sapper and ElderJS[2], so it's already ahead there...
Also, I've seen the maintainer of lit-element flaming people in comment threads. It doesn't inspire confidence.