Tolkien’s translation of Beowulf is better than Heaney’s as it is more like the original poem; which is also why people claim that Tolkien is a bad writer. That is to say, that Tolkien mostly wrote even his original works as if they were Old English literature translated as faithfully as possible into modern English.
I’ve read all of Heaney’s translation, and some of Tolkien’s, and Tolkien’s feels foreign, meaning that it feels spawned by far different consciousnesses, living in a different world. Which of course is exactly how in my view it should feel. Those who wrote Beowulf were very, very different from us.