Elytra. As @ImMattShadows said, customizing would be epic. I was actually surprised when I realized you couldn't.
I can't wait for OptiFine to update for 1.9. That's when the real fun starts. My frames go way higher than their already high level because I have a frame addiction; then there's zoom, shaders, and other cool stuff. Basically I want to ride an Elytra into a perfect shader sunset.
mine is probably all the cool sounds. doors sound different, chests, water, and most importantly rain. rain isn't so annoying anymore
Theres a lot of things i like about 1.9 c: Shields are pretty beneficial, Boats arent crappy anymore, The Elytras are fun to use, all the new sounds are great, and most importantly is the new stuff for the end :) Overall 1.9 is a really fun update, It makes regular Survival much more challenging.
Yeah, I haven't played that much of 1.9, but from the sounds I heard, it seemed pretty cool. And I agree with you when you said it makes survival more challenging. On my first night in 1,9, the new and improved skeleton destroyed me. :p
There are many interesting features about 1.9, that I think the majority of the Minecraft community hate. For instance, the 'pvp' in 1.9. But tbh, I kind of like the pvp in 1.9, gives a good chance for everyone to be able to pvp, and makes it so you can strategize what to do in any moment. My favorite part would have to be what I just stated, a fair chance for everyone to participate in the Minecraft pvp.
I actually loved it, it was a big step-up in a way. Minecraft isn't actually boring anymore. I wasn't a fan of it at first, but I judged it by what other people were saying. I have to say it's a good step-up and I'm sure a lot of people "hate" it because the pvp, but considering I was terrible at pvp it's no real change. 7.5/10
I don't like much truthfully. It's starting to feel like a mod more than just regular Minecraft now. I like the shields, duel wielding, new end and a couple more things, but I'm not a fan of the potion arrows and elytra wings. The potion arrows aren't needed, they seem like they would fit more in a mod, and I don't like being able to (semi) fly in just plain vanilla Minecraft. I wasn't too excited about 1.9, but overall it isn't bad.