I have used the activity 'summary' report for several activities - its a nice simple summary but I have a few comments on minor layout issues that would be good to clean up at some stage.
1) Species list tab: at the bottom of the list it says 'Showing first x of y records', and gives a 'rows per page' dropdown. Unfortunately there is no option to browse page 2 or 3 or four of the list if it is a long one. The rows per page dropdown only goes to 100, so if the activity has recorded more than 100 species you can't browse to see the rest of the list. If this is a limitation it would be better to have this as a 'top 100' species list rather than purporting to be a full list and not actually delivering the information.
2) Trending tab: The image tiling of the photos works for records with one or two attached pics, but for three or four it goes pear-shaped. The sort order of the photos is a little odd. It would be good if more recent photos appeared at the top of the list, so that this changes frequently. At present the order appears to be somewhat random and newly added photos may appear several pages down the list.
Both minor issues that could probably be resolved relatively easily and would make the report a little more useful/attractive.