It would really be nice if the WSAPI allowed for a larger maximum page size. There are many instances where I am pulling several thousand work items, and I am only in need of one field in the record. Having to pull the records 200 at a time means long wait times for the user while hundreds of individual pages are loaded.
The LBAPI page size should be some indication that this is certainly possible. It's max page size (if I remember correctly) is 10,000. I realize it's returning less information per record (OIDs instead of full objects) but with the optimizations made to the WSAPI in regards to bandwidth (not returning full collection detail) it seems like 200 is awfully low.
There are 2 problems here which are contributing to the slowness here. The first is the small page size. There are internal discussions happening right now about bumping this to 1000 (especially since now in v2.0 collections aren't returned in the request).
The second is that right now WsapiDataStore does its paging serially. The first page always has to be loaded serially, but after that the remaining n-1 should be able to be done in parallel.
There is a defect tracking the second item that will hopefully be addressed soon. Hopefully the first item will get some attention as well.