Yes, it's got some really nice features but it is a little clunky/complex compared to Zotero. I would try out Papers first before looking at Bookends...Bookends can work great, but it does take some work to set up.
Also, Bookends annoyingly checks to see if you are running the same license on multiple devices on your network, and if you have more than once instance running it forces you to close it down. This may seem superficially reasonable, but for someone with both a desktop and a laptop it's quite annoying. I emailed the developer about it and they didn't seem to get why this was a problem.
I'm using Papers 3 right now, and it is fairly buggy. I'm not a fan of switching to a subscription model (especially as I'm not an academic, which makes it too expensive), so I was looking for something else.
I like Zotero, but the lack of an ipad client is annoying. The file plugin requires more forethought than I really like. Bookends having a mobile client was one of the attractive features.
Also, Bookends annoyingly checks to see if you are running the same license on multiple devices on your network, and if you have more than once instance running it forces you to close it down. This may seem superficially reasonable, but for someone with both a desktop and a laptop it's quite annoying. I emailed the developer about it and they didn't seem to get why this was a problem.