SpeedCurve now uses EC2 m1.medium instances which have 3.75GB of RAM with faster CPU and network performance. For CPU heavy pages you should see a drop in overall load time. The connection speed for testing agents is still throttled to an average US connection speed so simple pages may not improve as much.
Overall this should provide more consistent results that are more on par with what an average user of your website might experience.
Do note that SpeedCurve's strength is competitive benchmarking and detailed build analysis. If you're after actual on the ground performance numbers then we suggest combining SpeedCurve with Real User Monitoring.