The thing they don't tell you about starting a lawn from Zoysia plugs is that Zoysia won't displace Bermuda, and if you have other grass or weeds, it'll take years for the Zoysia to fill in completely, if it ever does. One of the great things about Zoysia is that it grows relatively slowly, and isn't terribly invasive. Those are the qualities that work against you when you try to start a lawn from zoysia plugs.
Now if you do proper ground preparation, install the plugs properly, and water and fertilize properly, you just might get a nice looking lawn by the end of one growing season. Same as if you rennovated your lawn and seeded the prepared bed with one of the newer Zoysia seeds such as Zenith...
KB