Got my kit last night too. Some things I have noticed.
1. The new ball diff is smooth. But still uses no D-ring and tells you to glue it on to the outdrives. I can't understand why their diff rings are not D-cut in this day and age.
2. The transmission is smooth too. I had to add some shims on the diff and the top shaft. The top shaft had excessive play so I added a .2 mm shim. I think it was .3 for the diff.
3. The steering is different from the old TA/TB style, but closer to the 416 style if you know what I mean.
4. I am using hex screws where ever I can. Fine threaded Phillips are not friendly screwing into plastic. There are some high stress points that you should use steel screws instead of Al or even Ti.
5. Some brushless motors may not fit properly! That structural beam that runs above the endbell gets in the way of the solder tabs. This is with a trinity DUO motor style. I was able to get it to fit after hacking the A tab...
Other than that, the build is nice. Hope to get it running in a few days.