It's zippy enough, especially when you look at all the different platforms it works on. It's pretty far behind iOS, but then iOS has only a few platforms to worry about. Android is probably good enough especially when you factor in power consumption.

In the end though, it's all about trade-offs. Going with an Android fork gives you a pretty solid base to build off of. It's a nice option for app developers because the tools for Android development are excellent and the OS is well understood.