Summary: Actually, there are no real disadvantages of this Olympus 60 mm macro lens to consider. This is one of the best performing micro-43 lenses on the market now.
Pros: Very high image quality:, Dust and splash proof, Constant body length & focus limiter
Cons: Actually none, but if you are splitting hairs: expensive and big compared to the Olympus 45 mm 1.8, which offers the same optical quality (but no macro)