I most often search for articles - ATLA, JSTOR.
When I was writing my dissertation (oh, so long ago now!), I used interlibrary loan extensively. I now use ILL when researching a topic in the Roman Catholic or Anglican domains.
I have appreciated the space itself--the fireplace area, the meeting rooms. This may seem minor, but it is a lovely, welcoming space for a quiet moment of study.
The book scanner is amazing!