For the ADR Tool, several features are missing for perfect workflow:
1.) Show Takenumber.
Visibility of actual Takenumber for the Cutter and the voice-talent in the video- window
So far the only workaround is to copy takenumbers into another row of the CSV and import them as dialogue… 
2.) Second Video window or the ability to route the picture to another driver, without Blackmask and counter.
The Director does need to look at the scene without any mask or counter in the vid-window.
Only workaround here is to implement another vid-player and link it to Nuendo.
3.) Loop record
The ability to record in loop mode until the take is done. No possibility so far to do so with ADR mode active. No workaround here!
4.) Record light ( red (record), yellow (rehearse) and green (relisten)
There is no way so far to indicate the mode active in the ADR tool except in the Video - Window. This indication is far to small and not useful, nor is it visible outside the recording room.
5.) Transparancy of the Blackmask
Would be awesome to just reduce the visibility of the movie in pre- and post-roll.
6.) Possibility of active second marker track for notes.
Sometimes it is necessary to mark up spots and put some information for cut or mix into the session. The ADR markers can not be used for that.
All the above comes from 2 Years of experience, tracking ADR in Germany. All the above features are implemented into other Dubbing Systems and are absolutely standard in that branch.
Apart from that the ADR taker in Nuendo is working fine. But these features would make it much more professional and give me a even better argument in convincing companies using Nuendo instead of these other takers… Euro- FEG etc…
