In classical antiquity Propertius' eloquence was renowned. His successor Ovid referred to the blandi praecepta Properti (Trist. 2.465) and to blandi…Propertius oris (ibid. 5.1.15). Quintilian (10.1.93) stated that to his taste the most tersus and elegans Latin elegist was Tibullus, but sunt qui Propertium malint. Martial (14.189) mentioned the facundi carmen iuuenale Properti.
Turn now from the opinions of ancient authors to those of some modern commentators as they try to elucidate various passages as presented in the extant manuscripts, and you encounter not the adjectives blandus, tersus, elegans, and facundus, but ‘strange’, ‘obscure’, ‘odd’, ‘slovenly’, and the like.
A major reason for such striking differences of opinion should be evident. Ovid, to whom Propertius was blandi oris, read a text separated from Propertius' autograph by at most a few decades. Modern scholars, however, must form their text from a few relatively late manuscripts, none earlier than c. 1200, in which Propertius' eloquence has been obscured by over twelve centuries of careless blundering and deliberate interpolation by a succession of scribes.
A generally accepted example of deliberate interpolation in the Propertian archetype is found at 2.32.3-6:
nam quid Praenesti dubias, o Cynthia, sortes,
quid petis Aeaei moenia Telegoni?
cur tua te Herculeum deportant esseda Tibur?
Appia cur totiens te uia †ducit anum†?
(ducit FLP, dicit N), where the name of some neighbouring town is required in the fourth verse to balance Praeneste, Tusculum, and Herculeum in the preceding three.