Lately (last 2 weeks since I've updated to iOS 7) about 60% of the things I command to Siri timeout. It usually just spins, and I get the "I'm sorry, I can't take any requests..." error. Dictation gives up about a minute later, too. This is both on my home internet (10mbps) and 3G (full bars). While iOS 6 wasn't always accurate, it at least took my requests most of the time. Really annoying, since Siri / Dictation was the whole reason why I bought an iPhone 4S. Anyone else notice this?