I have been using SU 16 for about three weeks. I am having two main issues. First, my main model is huge! 180 MB- after purging at the end of every day. A similar model I made in SU 15, with double the components and materials was only 130MB. Second, I experience periods of random slowdown. Its never the same action that triggers the slowdown. Sometimes it is when I am trying to apply materials. Other times, I tried to move a component. And saving the models, which once took about 15 seconds, is taking upwards of 45 seconds. I can go get coffee, come back and the ■■■■ thing is still saving. My coworkers are having very similar issues, so I know its not just my models. They are having issues of entire features being unavailable (like textures, or materials. Just ~poof~ gone from SketchUp). We have resolved this by uninstalling/reinstalling, only for a new issue to pop up. Wish I had held on to SU15 for a little while longer.
@JimD: I was under the impression, once you used v16 for a while, you can’t register your v15 anymore. So you’re stuck with Make (and in violation with the official user agreement)