Firstly you cannot compare the both of them because they are two totally different attractions completely.
The studio tour is amazing but it is a tour/museum with no theme park rides or you can’t go into the likes of ollivanders etc. it’s amazing in itself because it was where the movies were filmed and it features all the actual sets, props and costumes from the movies.
Wizarding world of Harry potter has the rides and the actual shops. Not to mention the soon to open diagon alley. Plus it’s in the usually sunny Florida.
It really does bug me that people try and compare the two. Or say that the UK doesn’t deserve a theme park because we have the tour. Yes the UK has the tour and the movies where filmed here but isn’t that even more of a reason as to why we should eventually get a Harry potter theme park? Not all of us uk, Irish and European potter fans can afford holidays to florida, Japan or Hollywood to visit the theme parks. (You’re talking a good £2000+ for the whole trip)
When I met Chris Rankin (Percy Weasley) he though that the Uk will eventually get a theme park but I just hope it isn’t just some tiny little area with one crappy ride but the same as Floridas ones.