In Sonar X3, is there any command to combine/compress all the takes into a minimum number of lanes?   Across a song, I'll do 50 takes.  But for each section there may only be 10 lanes actually needed.  Any way to reduce total number of lines to minimum while maintaining 1 take per lane at a given time?

To have a command like that, it would have to read your mind as to where to put each take and it would have to know how long the lyrics are, when they come in and when they end.
 
No command, but you can just drag them to any lane of your choice and delete the empty lanes.

Not at all - this sounds like the old feature we had in SONAR 8 (Combine Layers?).  It might not be perfect (and wasn't always), but it's really needed and doesn't exist for Take Lanes.

I'm so stupid!!

CJaysMusic
I'm so stupid!!

No, you just read too fast. For "stupid," there's television.

KPerry
Not at all - this sounds like the old feature we had in SONAR 8 (Combine Layers?).  It might not be perfect (and wasn't always), but it's really needed and doesn't exist for Take Lanes.

Yes!   I thought for sure it was in a past version but I couldn't find it with The Googles.

So I assume then this was removed and not re-implemented?   It was a handy, time-saving feature for me.

No, it hasn't been implemented for Take Lanes.   There have been many discussions about the topic since X2 came out, but they all go around in circles in the end - it seems to always come down to how should Lanes be consolidated.  I recall many questions and complaints in the pre-X2 era for how Layers handled that aspect, so I can understand why CW would be leery of going down that road again.  
 
That said, X3 did introduce the ability to delete empty Lanes and muted takes, and also to flatten the Comp to a single clip.   So maybe they are heading towards something like a consolidate at some point...
 

stevec
 
...and also to flatten the Comp to a single clip.

With this feature/ability, why is the removing the lanes you don't want so important?
 
After I comp a trk, I collapse it. Done. Move on.

It is something I would use before beginning a comp.   The way I typically record a vocalist for a pop song is section by section, part by part.   By the time I'm through a typical song, there are often 60+ takes with a lane for each take.  So this creates this big grid of takes/take lanes that is populated from the top left to the bottom right at the end of the song.   It's unwieldy to deal with and creates a lot of scrolling.    It would neaten the work area and reduce the total required number of lanes if all of the takes were pushed up to the topmost lane it could occupy without covering a separate take.

What Jack Ludden said.
Also, here is the discussion from the last time I brought this up.