The crossing to Nador is probably easier as you would be landing directly in Morocco, and passport control would hopefully be done on board.
I did the Almeria to Melilla crossing in September, arrived late at night so needed to find accommodation in the Spanish enclave before tackling the border. Much of the town appears to be one large red light district and noisy.
The border at Beni Enzar was a seething mass of humanity, much more dramatic than Fnediq (next to Ceuta), however the entry procedures were much the same. Can't remember whether there were 'helpers' but wouldn't have used them anyway.
Tim