using BOINC with an SSD isn't going to substantially increase your production or reduce your run times. as Larry mentioned though, you do have to be concerned w/ SSD wear. the way to avoid this and still use an SSD is to install the program files (the BOINC program itself) to the SSD, and install the BOINC program data directory to a local HDD volume, not the SSD. then all the data being downloaded from and uploaded to the servers of the various projects in which you participate will consist of reads and writes to and from your HDD, thus preserving SSD life.
i'm sure quantities (on the order of tens of terabytes) of BOINC project data have been written to and read from my HDD over the last nine months - the length of time i've had the SSD in the system - and yet my SSD life is still optimal: