I really like a well worn bronze especially if there’s some varied patina going on. Collect what you like.
This is the most worn but still identifiable coin in my collection. The ID is made by recognizing the portrait as belonging to Julia Domna and corn ears and long torch as belonging to Ceres. Julia Domna, AD 193-217. Roman Æ as, 13.49 g, 27.6 mm, 5 h. Rome, AD 198. Obv: IVLIA AVGVSTA, bare-headed and draped bust, right. Rev: CERES S C, Ceres standing left, holding corn ears and long torch; altar at feet, left. Refs: RIC 870; BMCRE 781; Cohen 19; RCV 6636; Hill 346. Here's the example in the British Museum for comparison:
Personally, I really don't mind honest wear on ancient coins, and I tend to consider it a layer of historical use and appreciation rather than damage. Attractively worn coins such as these two are always welcome to my collection, and many other ancient collectors appear to think similarly: Faustina the Younger, Roman Empire, sestertius, ca. 161–164 AD, Rome mint. Obv: [F]AVSTINA AVGV[STA], diademed portrait right. Rev: IV[NONI] REGINAE, S-C, Iuno standing left with patera and sceptre, peacock left. 30mm, 27g. Ref: RIC III, 1651. Caligula, Roman Empire, As, 37–38 AD, Rome mint. Obv: C CAESAR GERMANICVS PON M TR POT, bare-headed head left. Rev: VESTA, Vesta seated left holding patera and sceptre. S–C. 28 mm, 10.18 g. Ref: RIC I, 38. Ex Spartan, ex D. Pichler. Is it wise to collect such specimens? For a start, collecting ancient coins seems quite the opposite of a clever financial move. Furthermore, there is a high level of irrational geekiness to spending considerable time and money on small chunks of old metal. Hence, I think of my collecting not as a smart decision, but as an enjoyable and educational personal folly. This hobby has given me tremendous aesthetic pleasure, lots of fun discussions with fellow collectors, and many a joyful and enlightening hour spent on reading up on the history behind these objects. None of this has much to do with rarity, grade, or resale value – and therefore I continue to simply collect coins that I like, can afford, and find fascinating, no matter how worn or common they are.