As a couple, it depends on the day.
Give it a sharper, ghost-tour-specific verdict instead of the recycled 'depends on the guide'. McGee's Ghost Tours (running since 2007, ~800 tours a year, consistently top-rated) is the established pick: costumed guides walking the Golem-and-alchemist legends through the foggy, gas-lit back lanes. The real, specific downside isn't 'a good guide makes it' — it's that the routes heavily overlap the same Old Town streets every daytime free walking tour already covers, so if you've done an orientation walk you'll recognise much of the ground, now retold as spooky anecdote. It's light entertainment dressed as history with tame 'scares'; book it for the atmosphere and the storytelling, not for new territory or genuine frights.