I've done it for a number of years but last year the "straw" bales had more seed than not and they all grew large grasses next to my plants. You can't hoe the weeds and and its hard to pull the larger weeds with heavy root systems because it tears the bale which in turn disturbs the root system of the plants.
I think due to it being the latest craze, the suppliers ran out of straw bales and substituted hay, thinking that people wouldn't notice.
Before that, most years my bales stayed together really well and I could use most of them again the following year with another application of a fertilizer. Last year I moved the garden so had to use all new straw bales.
It is certainly easier than amending the soil and I found that they retain water fairly well, except in the hottest days of summer.
They do attract mice and then snakes follow.
I like that you don't have to do much bending to plant, weed or harvest
