A:AnswerThe sound is not bad for a small speaker. Of course it isn't going to sound like high quality stereo speakers, but it does a nice job and if the volume isn't turned too high it sounds better
A:AnswerWe use it to turn lights off and on, lock our doors, ask questions get weather reports in the morning while making kids lunches. You can to a lot with Alexa.
A:AnswerIf by updates you mean new skills and integrations, then yes, when you configure/enable skills with Alexa they are available on your other Alexa enabled devices.
A:AnswerMichael, i'm not sure how many decibels the speaker reaches for the Amazon Echo but I can assure you that it's loud...very loud. I do have the Amazon Echo which is the largest one and to me the loudest but my sister has the Amazon Tap and Amazon Dot and she loves both of them. Of course the Amazon Dot is not as loud as the other two but it's still an amazing sound considering such a small device. Good luck with your choice!