A deal-breaker? Unless you're Thumbelina, probably not.

Both the HTC EVO 4G and the Nexus One are running 2.1, the latest version of Google's mobile operating system. Despite the matching versions, however, the user experience will be quite different on the two phones.

The reason is that the HTC EVO 4G runs user interface, while the Nexus One uses the stock Android interface. The Sense interface gives Android an entirely different look, with specialized home screen widgets and custom navigation tools. As far as which is better, it's really just a matter of personal preference.

One area where the Nexus One's setup will have a distinct advantage, though, is in future Android upgrades: Given the fact that the phone is running the stock Android interface, updating it to a new OS version will be a simple and likely delay-free process (the fact that the Nexus One is Google's baby probably won't hurt, either). Custom interfaces such as HTC's Sense tend to take more time to update, as the manufacturer has to rebuild the interface around the revised platform.