I've also had nothing but troubles with NC. I tried the AIO option and while it was easier to setup, it was still slow on both a VPS and my local unRAID server. I find that if you're simply using it as a sync point for apps instead of regularly using the web portal, it's ok. Seafile is insanely fast. But it stores the data in chunks on the server which some do not like as it can complicate backups. I work around that by just backing up from one of my always on clients since the seadrive client mounts the chunks into usable format. That works great.
Then again, NC is way more app than I need.