One cannot compare these two, not even remotely. From a purely literary point of view, Tolkien would probably win over Herbert in each aspect.
On the other hand, Herbert's strength comes with the psychology of characters and the philosophical system. His style is unique, even today.
If you need to compare Herbert to someone, choose his sci-fi peers from the same time period. Compared to Herbert, their works were
terribly sterile and typically Anglo-Saxon. And yes, I would vouch for Herbert anytime.
Tolkien is the classical story-teller, experimenting with new worlds rather than with literature itself. Common reader cannot dismiss him lightly, since Tolkien is not your typical wannabe writer; his education and career helped him to create work, lying beyond usual criticism.
Approaching Tolkien requires modesty. One can dislike Tolkien's books, yet should not jump to false assumptions. Let me wildly guess why you
formulated the question this way.
For demonstration, I will use my web novel Sovereign. Its style is probably much closer to Herbert’s than to Tolkien’s. I am more focused on the present scene, not teasing reader's patience with long descriptions and unnecessary information. Why do I do that? Because I dislike classical narrative? No, it is because the literature and its consumers have evolved since Tolkien’s time. Authors have less time to catch their
fishes … er, readers.
Thus, judging from that perspective, Tolkien may feel heavier and more cumbersome because Herbert offers a more modern and "sensational" flow of events. Even to drink a cup of water might bear plenty of meanings and facets in Herbert's Dune. Just remember the very first scene, in which Paul eavesdrops his mother and the old witch.
No sentence is wasted on banalities. Never.
Tolkien builds the tension slowly. With a shorter attention span of present readers, they might have problems to enjoy the Lord of the rings. But this is not
a question being better or worse. of