I'll wait for the update to show up on the Google Play Store. But... I just started using Hangouts vs. using the default Messages app. Is this a big deal? If so, why? I read about this but article didn't tell me why this was important or if it did the fact didn't register with me. TIA.
The biggest user facing change will be for those that have hangouts and text messages with the same person and have more than one thread open because of that. This is a feature that we've been waiting for ever since we found out that Hangouts was going to handle SMS & MMS.
It essentially means you don't necessarily have to think about how you want to talk to someone unless you want to specify what manner they receive your message in and/or you are trying to specify whether you use mobile data or your text allotment, etc. You are able to choose how to send each message without it disrupting your conversation thread the way you read it. More importantly, the other person can send you a message in whatever way they want to and it all shows up the same to you. If you don't actually use hangouts currently for the hangouts feature (if it is only SMS/MMS for you), then it probably isn't going to be that big of a thing.
Behind the scenes there are some aethetics and menu cleanup items as well as some bug fixes that make it nicer as well.