I have been to Shocktoberfest at Tulley's farm every year for about 8 years. I can't speak for other local Halloween events, but I'm lead to believe Tulleys Farm is one of the better ones. And while it is good, Scarefest at Alton Towers is usually higher quality, and certainly better value.
Tulleys Farm throw an impressive event for a small farm, but beyond the Haunted Hayride (which is fantastic, despite being exactly the same every year), there is little on offer, with the actual scaremazes being low quality. The "actors" are just locally recruited kids who are normally bored after the first 2 nights and stop trying.
Not to mention it's as expensive as a day ticket to Alton Towers nowadays: £36 online price for just 1 go on all 8 attractions (fast track or extra goes cost more) vs £36 Alton Towers online day ticket (obviously most mazes are now upcharge, but still a valid price comparison IMO, since I get an entire theme park for my money at Alton.)
I love Tulleys, but there is no point glamming it up beyond what it is. It is a great local halloween event, but it has nowhere near the polish or professionalism as the events at Alton Towers or Thorpe Park.