i just received my copy of 3ds max 9 – exactly one day after the press release of its availability. i’m always suprised how fast i receive the latest 3ds max package if you’re part of the subscription programme. really nice service, i can recommend it if you always want to upgrade and not skipping any version. first of all i don’t have a 64bit operating system (the new version has been re-compiled for this platform) so i can’t get out all of the performance promised, but nevertheless it’s time for first impressions.
my main interest was the speedup of the viewport when using tons of polygons. let’s check this: wooow! i’m definitely amazed by the speed improvements – it makes modelling with thousands of polygons so much smoother. you’d think you have a new cpu installed in your computer when comparing to to previous version of 3dsmax. the docs describe this hot feature like this:
“core performance enhancements have been made to 3ds max 9 to maximize your productivity and accelerate your creative workflow. for example, enjoy greater viewport interactivity when working with dense meshes and switch between high-res and low-res bitmap proxies to allow for better interaction.”
second interest was the inegration of the latest version of mental ray (3.5) – i’m a vray user but i normally use the render which is most suited one for the ongoing project and mental ray is part of the package by default – so there are enough reasons to take a look at it. first think i like: the new presets like car paint and architecture materials – very useful, but i hope that mental ray will set up a similar materials exchange platform like the vray or maxwell renderer community did lately.
last but not least: do my tools still work in 3dsmax? i always install polyboost before i start working but you shouldn’t with 3ds max 9: polyboost announced some days ago that there’s a new version on the way and so i stick to 3ds max 8 until they have published it. modelling without polyboost is a pain for me 
from other publishers of plugins i heard a lot of rumbling and they all need to re-compile their plugins. lucky me, i nearly don’t use any plugins.
so, this is just my first 5 minutes impression. more to follow when i digged the manuals. stay tuned.