Here is what our monitoring is showing for 5 minute average pingtimes for various locations out of Softlayer Dallas:

Houston, TX - 13.623
Miami, FL - 31.289
Washington, DC - 34.859
Los Angeles, CA- 44.401
Chicago, IL - 33.198
Trumbull, CT - 54.88
San Francisco, CA - 44.905
Toronto, Canada - 39.973

Seattle and DC will be good for their respective coasts, but overall you can see Dallas is not bad at all. This should go down significantly when using an ISP peer.