Can Someone Explain Google Experience Launcher?

I am currently using an iPhone 5 and want to move to a phablet, so I am looking at the Note 3.

Unfortunately I've never been a fan of the samsung software/UI style. However, it seems as though finally you can use the google launcher on any device? Does this mean I can get the Note 3, set the GEL as my launcher and then basically be running a stock OS similar to the Nexus 5???

Any downsides to this over getting a stock android device apart from getting updates later? Does it automatically set it to use stock android apps for messaging, music etc. or will samsung apps still launch instead?