I asked a friend at Astronautics about the ZS-1, and he said:
 I talked to a guy who has used the one we used to have
here.  He says for
scalar operations, it's as good as a 386.  For purely vector operations, it
might be equivalent to a 1 GHz Pentium.
If you are looking for scrap value, it has 60 amp 5 volt power supplies and
old SCSI hard drives.
He also said you might have trouble with your electric bill. 
- John