I'd like to try, but I'd probably not end up using it because it's not open source. I feel silly for rejecting a product based on that, but openness is important to me. Here's for hoping they open source it soon!
I don't think you should feel silly for rejecting it for that reason, its a very valid complaint.
Same for me. Some of the changes Opera have been making are interesting, and they do seem to be doing more with the UI than Firefox and Chrome, who are removing as much UI as possible. But the social messenger stuff doesn't interest me, and having stuff like Facebook hard wired into a browser without having the source to know what it's actually sending to them really puts me off. I know Chromium is open source, but the interesting bits are in the stuff they've added on top, which is not.
My reasoning for not using it is largely the same. Especially when there are plenty of high-quality open source browsers, including two major ones (Chromium and Firefox). I'm not willing to switch to a proprietary browser just because it's a bit shinier.