12.9 2015, 10.5 2017
11 inch Pro 2018
Screen
Pencil
Speed
Battery
New design. I love the square look or flat sides.
ASK is better. In my opinion.
Less weight.
Black bezel no matter the color.
Speakers are much loader then my 10.5 not my 12.9.
Front facing camera. For FaceTime use is noticeably better.
USB C. Reverse charging. WIN!!!
Screen is
not better
The screen size on the 2018 Pro is the same size as that on the 2017 Pro 12.9".
The Display resolution on 2018 is the same on the 2017 - 2732x2048 at 264 ppi
Camera
loses an element due to thinness
2018 -12 megapixel with 5 element lens
2017 -12 megapixel with 6 element lens
Both record in 4K
Front facing camera on both is 7 Megapixel, so there is nothing noticeably better.
Battery life is the same - up to 10 hours
No headphone Jack on the 2018
Second Gen Pencil draws the same way as the first gen. Same Tip. Same Latency. Same Pressure points. Same response time. Its the same pencil, repackaged with a few new ways to interact, namely wireless charging and pairing and touch features.
Processor is faster - I expect this.
RAM is the same 4gb unless you purchase the outrageously priced 512gb version which gets you 6gb
2018 has FaceID, while the 2017 has TouchID. That's a user preference.
The new iPads are gorgeous, but nothing really new or must have features for me to upgrade.
FaceID would be nice to have, but I will not have a better experience on the 3rd gen over my 2nd gen.
I will wait to see what 2019 has to offer, or even 2020.