I used Trove as a selection aid to search for Stage 1 resources, for a unit of work on minibeasts. I found that it was largely unsuccessful, with a few unfitting newspaper articles and images that were unavailable. Changing my key word search in this instance to insects proved only slightly more successful. But once more, the resources were not entirely appropriate or useful. I think that Trove as a selection aid is much more suitable for locating resources for older students (particularly secondary). That is not to say I would discount it entirely in a primary school setting.
I believe its value is largely in the provision of a variety of resource formats, including audio files, maps, letters and newspapers etc. The application for these resources across the curriculum is wide and varied.