The query with count is slower because it has to read all the data (to count it).
When you run the other query, you are only fetching a first page of data, so the execution (reading from the cursor) can stop after you have your first ten results.
Try loading to 100th page with your first query, it will likely be much slower than the first page.
If selecting a count online is too expensive, a common trick is to select one item more than you need (11 in your case) to determine if there is more data. You cannot show a page count, but at least a "next page" button.
Update: Are you saying the count query is only slow when run through ADF, but fast through SQL Developer?