As you know, I've been using Maya for quite some time, but a couple of years ago I moved to Maya LT a couple of years ago, since that version is aimed at game developers. The last Maya (non LT) version I used was Maya 2016, and it has changed significantly in some areas in the last few years and three releases.
In Maya 2017, the application adopted Arnold renderer in favor of Mentalray. Now, you can also use the Arnold renderer as a preview renderer in the viewport. Previous versions of Maya have included Vierport 2.0, which is an updated and more powerful viewport rendering engine that supports better display of materials textures and lights, and was supposed to be used as a way to setup lighting and materials in a more interactive way. Now, with the Arnold viewport you can do the same.
You should keep in mind that using this viewport renderer can consume a lot of system resources. During my tests, when the viewport was activated on a simple sample scene, the CPU jumped all the way to 100% usage during while the rendering was processing, and GPU is also important. That means you should make sure you have a powerful system and card if you want to use this feature. I have a gaming card (Geforce GTX 970) since I work on game development, and the slowdown was notorious.
Another interesting feature is the Cached Playback. What this feature does is store cached animation in memory (RAM) so it plays back faster, and it aims at allowing you to work faster since you'd be able to watch the animation play in real speed in the viewport, instead of using Playblasts, which is what Maya users have been using until now.
If you have used video editing applications, you know you can cache your media so it plays faster, but that you need a system with a good amount of RAM to do it. Cached Playback works in a similar way, and it can take up a lot of RAM very quickly, although the benefits are really significative.
For my tests, I used two different animations. The first one was a single-character animation, with no background, that was just a couple of seconds long, and it only increased my Maya memory usage around 200 mb. The second animation was over 500 frames long (17 seconds) and included a lot of action (albeit it still featured just one texture character and no scene), and it increased the Maya memory usage by over 2Gb. In both cases, using the “play every frame, free” setting, the cached animation played faster than the non-cached animation (around 250fps versus 100 fps).
As you know, Maya is a 64bit application. So, if you plan to use Cached Payback for complex animations and scenes, it's recommended that you have a good amount of RAM on your system.
Another thing I noticed is that some deformers have been modified so they run on the GPU, not the CPU. BlendShapes, SkinCluster, Cluster and Wire deformers are among the ones that run on the GPU, which means they should work faster. However, I think that may benefit mostly those working with high resolution characters and complex scenes, since animations using low resolution models (for example, game modes) already play really quickly.
This update also includes some pre-rigged humans from renderpeople.com. Renderpeople.com is a website offering 3d human models for renderings (more specifically, architectural renderings). These characters are rigged using Human IK, so you can start animating right away. According to Autodesk, they are included so you can use them to start practicing character animation, but you can use them for any kind of scene. The software also includes some motion capture samples that you can use for your animations.
Autodesk has also opened a website where you can provide feedback and request features. Personally, I would like to request them to take Softimage's Face Robot technology and implement it in Maya somehow. I still have an old version of Maya and Softimage because I exchange data between them (depending on my projects, I make a facial rig in Face Robot and then I export the animation as Blendshapes back into Maya), and I would love to have those capabilities in a new Maya version, because I find it extremely weird that a software from 2015 (Softimage) manages to produce better keyframe-animated facial animation than more modern applications.
Maya 2019 is interesting to check out. I like how you can use Cached Playback or the Viewport 2.0 to preview how your final image would look on Arnold. If you use Maya (meaning the “full” Maya animation software, and not Maya LT), chances are you are working on higher end 3d animations, so you can really take advantage of those. However, if you are like me, working on realtime graphics for video games, chances are your animations are already playing in realtime (be it 30fps or 60fps).
You can find more information about the new Maya 2019 at Autodesk's webpage. Autodesk has a wide variety of purchase options include a great suscription service and a free 30-day trial.