As offered, I started testing with CP4 Beta (with CJlib 2.0.14) on a test site. There are lots of exciting options though things have not gone so smoothly for my test.
1. I upgraded a CP3.x installation to this one. I had multiple fatal errors on the front end. I resaved the CP menu items, uninstalled and then reinstalled CP4 which resolved the fatal errors
2. After upgrade, all ACL for polls became blank. Had to reset the access level for each poll to allow me to see on front end
3. Categories were erased and existing polls had no category assignment. I remade the category and assigned polls. Allowing me to see and test on front end
4. The toolbar styling is broken. It seems the bootstrap css file is there, but styling of the toolbar does not appear, see example below:
After loading a lot of CSS from the Joomla protostar template, the layout was fixed.
5. Seeing this below the poll (same example as above): Loading suggestions, please wait...
6. There does not appear to be a backend option to load bootstrap/jquery like in 3.x
This is my initial testing. As mentioned, this is very exciting and will be great once I sort out some of the above.