Very extensive interview process that lasted more than a month, end-to-end, and included 8 interviews, 4 over the phone and 4 in a row for the in-person. During that time, at least, the recruiting contact was pleasant and very responsive.
Then nothing. Radio silence. No updates, no decisions, no "We're still in the process"...nothing. Sent a follow up after one week. Another after two weeks. Both were flat-out ignored, without even the courtesy of "The position has been filled".
It's like going on 8 great dates then finding out they've changed their number and filed a restraining order on you.
Being super selective about your hires is understandable, it's a great thing and helps ensure you've got the best team possible. At the same time, though, show that you respect the investment that your candidates are making, even if they aren't the fit you're looking for.
I can only recommend prospective candidates pass on this group.