It works okay. I like that it's universal (the same assistant on my phone, on my home devices, in my car, in my earbuds). I like that it does tasks right, but you have to know how to phrase them (my most common is probably "remind me to X tomorrow at X time"). Setting alarms and timers, creating calendar events, asking about the weather on a specific day or in a specific place, asking how long it'll take to walk/drive somewhere -- all good. But anything more complicated than that and you get erratic behaviour. From what I've seen with my friends interacting with Siri, I'd say they're about equal in capability.