Never been myself but I've watched a fair bit of footage from people who have and the activity in the basement seems to be the real deal. The scratching phenomena especially - that's not easily faked on camera.
What I would say is go in with your expectations in check. Too many people rock up to these places having watched a load of YouTube videos and they end up manufacturing experiences in their own heads. The Sallie House has a decent enough reputation without needing any of that nonsense.
If you do go, document everything properly before you start. Baseline readings, temperature, the lot. And take someone sensible with you not just someone who wants to scream at every creak. Be interested to hear what you find when you get back.