https://docs.google.com/document/d/155UOVTLYBcNRWTDKAkLLStFbpCMv0eK4f1gkNoyRiZ0/view
Bitmain should ship those with DHCP enabled. Save a people a lot of time.
I think that the fixed IP setting is the better choice. Assuming that you want your Antminer to mine independently, without 'babysitting', the last thing that you want is expiry of a DHCP lease. DHCP is fine for a PC that you periodically connect, and the lease gets renewed and runs for the duration of your PC use session. With a 'permanent' connection like a miner, this is a bad choice. My Ants have been running for weeks or months without interruption, the last thing that anyone needs is a lost connection because the DHCP lease happened to expire.
Cheers