I think that much of this can be read as opinion. It is difficult to assess whether or not such a statement is true because it is a matter of opinion. Take some of the items presented in the statement and one can see that interpretation of Bacon's prose becomes critical. For example, the "density of thought" line could be seen as valid from one's point of view, while another could feel that the essays offered are sparse in thought. In terms of assessing the density of expression, all of them are in the essay form, so expression seems to be limited in that regard. The effusive praise that is featured in the sub question is even subject to individual analysis. While I think Bacon is an stellar thinker, the idea of "impressive loftiness" might not be something that I share in reading his work. I think that in assessing the statement, one has to keep in mind that this is personal reflection, what an individual feels about Bacon's work. It can be debated and assessed, but it can only be true so far as opinions can be considered to be true in the speaker's mind.