First, get over the old style infterface. So what? Here's my 1 week of use feedback.

1. Is it easy to use? Yes. I worked it out with minimal/zero references to the help files.
2. Does it work? Yes. Everything worked as expected except images in the RSS feed (more on that below)
3. Is it reliable? Yes. I've been letting it run for a week now watching the newsletters come exactly as expected.
4. Is there support there for you? Yes. Images were not coming through on my RSS feed. I emailed support and next day had genuinely useful responses. The problem was with my configuration, not Feedblitz.
5. Is it configurable to produce great looking newsletters? Yes.

Any downsides so far? Only that their new product is going to be way too expensive for my non-profit business. The version you get here will do everything I need it to do, except two things - I really wanted the ability to resend newsletters to those who didn't open them, and secondly, I'd love to set up rules to automatically purge emails that don't engage with the newsletter.

But overall, I'm very happy with this - taken tier 2 and might upgrade to tier 3 just to be sure I have enough to cover subscriber growth.