Is The Tempest really a great play?

Is "The Tempest" really a great play? In some ways, of course - starting with the language. It's Shakespeare at the end of his career, so the imagery is fully incorporated into the verse, not external, showy baubles as in the earliest works, not a lot of set pieces (other than "our revels now are ended") but just line by line, there's hardly a passage you couldn't isolate and enjoy, wonder at, revere - from descriptions of the landscape, the nautical scenes, many references to the tides - it's his most geographic and topological play. Also, Shakespeare recapitulates many of the themes running through all of his works, including authority, imperialism, colonialism (yes, these issues are in the other comedies, believe me), and perhaps more than any other play he reflects on the process of making art and drama - particularly poignant in that The Tempest is his last major work. Also some scenes that are challenging to all directors (the storm, the pageant/masque) and some pretty easy and always funny (the drunken louts, the ingenue lovers). All that said: in some ways it's a play more appreciated than truly loved. Don't we have to admit it: Prospero is a bore and a controlling bully. The play is completely devoid of surprise - for the audience - as we see Prospero controlling everything and everyone, through his minions, Ariel and Caliban. The conversion of the usurping duke is preposterous (though not without precedent in S's comedies and romances). Is it really a great play? Or more of a monument, an object of study and conjecture, and a curiosity?