Can vouch for this. We've gone through three water heaters and a bunch of maintenance on those, and in the same time the solar collector has been replaced zero times and required no maintenance. It's honestly quite impressive.
I heavily vouch for them - the tech is so effective we cover them with a shadecloth in high Summer because the water gets too hot (Off-Grid property in Central West NSW, Australia).
Ours have lasted over 10 yrs without maintenance.
One downside is that they're not ubiquitous so some plumbers may not want to work with them.
They're so good I'm surprised I don't see them everywhere.