The big deal with 10.2 is that it adds Camel Audio's (which Apple purchased earlier this year) Alchemy synth. This is a synth with a wide range of talents, from creating sounds using samples and different kinds of synthesis, to multiple filters and modulation options.
Other than that, Logic Pro X 10.2 provides an easy way to distribute directly to Apple Music and its Connect feature, which was also introduced in a Garage Band update earlier this year.
This can be a big update if you want to load all 14 Gigs of available sound files, but be aware that they tend to lean more on the dance music/EDM side of things, which is great if that's what you need.
Here's a video that takes a look and listen to Alchemy.