Another app you can try is Cyclemeter. It's now available for Android and if it's anything like their iOS version, you're going to have a tough time beating it. I tested just about all the iOS cycling apps against each other and every time, Cyclemeter came out leaps and bounds ahead.

When you are testing, I hope that you do not have any other apps running in the background. Your cycling app should be the only app running when you are testing. The more apps that you have fighting for CPU time, the more your app has to share. If the programmer has a poor parsing routine, it will take more time to get a point plotted on the map and a longer delay in displaying the data on the screen.