Yes the lane height restrictions are still there. Mute and solo buttons on take lanes are almost redundant now thanks to the "all new" comping tools. That really is superb and every bit as good as it looks in the video.
Yes the main track is now used displaying a "comp track" when the lanes are open, that's a virtual track of the current promoted (audible) takes. When the take lanes close the track displays the clips you hear rather than the top lane.
I'd still like to see the lane height restriction addressed at some point especially the minimum height now the mute/solo buttons are no longer needed to comp with.