the smaller ones don't seem to have much work at the moment
I tend to keep HSTB and BETA projects always selected as these tasks are not very frequent, so if you're after a given badge better to grab them when you can.
The other projects normally tend to give out constant work; given any current project circumstances.
Every month WCG releases a news article for each project where they give you an exact up to date on what's happening with the project, including availability of tasks.
https://www.worldcommunitygrid.org/abou ... layNews.do
From the August news article for OP-C19
GPU version: The World Community Grid development team is starting to create work units for initial alpha testing. Their current issue is creating work units that can run on both CPU and GPU, rather than needing to create two different versions, which would add complexity to the project. The next step within IBM will be a security review of the new version. The work is ongoing and there's currently no estimate for when it will be completed.