Many people where shocked when they switched from beta to release and noticed their latency had increased twofold. I have experienced this too. I had a latency of 100ms in the beta but it is over 250 in release, although it still plays fine. Recently a fan posted a thread asking about this issue, with the following first post:
"I live in Toronto and I'm always getting 250-320ms.
My question is, will pings always be this way? Is server maintenance still going on? Can we expect pings to drop?
My other question is, are the Americas region all connecting to the servers in California or are the servers spread out across America so that those who are on the east coast connect to the closest servers but still be in the Americas Region along with everyone else?"
Bashiok responded on page 3 with the following response:
The latency indicator in-game is not a simple ping like most games, and is actually a full process of the game sending an action to the service, the service processing it, and returning it to the client. This means that the latency indicator actually gives a more accurate account of what the experience is for game data, but in comparison to other games will seem high. We're more interested in issues where there is actual performance degradation, and certainly there may be, but the in-game latency number is not a simple ping and therefore shouldn't be used literally as a measurement against performance elsewhere.
I should add that the correct forum for this is really the Technical Support forum.
A ping is defined as the time it takes to send a packet of data to the server and receive it back. As explained by Bashiok, the Diablo 3 latency meter actually measures how long the server takes to process your request and not just receive your data, which is why it may seem high compared to games which don't measure this.
If you are getting laggy gameplay, make sure you are not running any downloads in the background and also make sure you have the correct region selected from the game settings/
As your game is running smooth, I wouldn't really worry about this.