To avoid the 'swamps' of standard Italian Tasso criticism, one has to go back to Giacomo Leopardi's 19th century Dialogues (see) or read essays written by foreign scholars. For example, very interesting are the -- however brief -- remarks on Tasso made by CS Lewis while studying Milton in A Preface to Paradise Lost. Here the Italian poet is not described as a madman nor as the author of 'unbearably boring Christian stuff' as it is often the case in this neighborhood, but as the learned and brilliant poet he was, together with a lot of precious materials on Renaissance culture in general. Dante also is dealt with by Lewis in a quite different manner from the standard pattern in Dante's home country.
It is really a pity that Lewis seems to be familiar only with the Gerusalemme Liberata and not the Conquistata, let alone Il Mondo Creato, otherwise his cross-references with Milton would have been even more poignant, though probably his admiration for Tasso might have dimished. On the other hand, A Preface to Paradise Lost is highly recommendable for its insights into a number of different subjects, from the Church Fathers to Napoleon to the Disney cartoon movies.