Yeah, 12 bits is fine for a lot of uses, especially with averaging.
My recollection is, in terms of resolution, the HP DSA lineup was:
35660A/35665A = 12 bit
3562A = 14 bit
3567A/3565S = 16 bit (I have one)
35670A = 16 bit
Amazingly, the 35670A is still in production, but is scheduled for discontinuation later this year. It's had a very long run.