Keeping it short: all Elevenfour styles and plugins for WoltLab Suite 2.x (WBB 4.x) are incompatible with WoltLab Suite 3.0.
As always before a new software version is released: designers and the developers are asked if they would support the new version. And is the same with WoltLab Community Core 3.0 (formerly WoltLab Community Framework 2.2).
To make my decision a little easier I have asked you which styles you wish to use with WSC 3.0. After closing the poll at 2016-07-27 (after almost 3 months) I present the results of the poll. At first have a look at the image.
As you can see it's pretty clear, that the X-Style is most wished. Here are the numbers:
A big thank you to all who participated in the poll.