I've been copying and pasting and moving a lot of midi tracks with no problems.

Jlien X
I find copying/moving clips (without dragging) in X3 still inconvenient because if you copy the clip in Lane 1 and then select Lane 3 and paste it, the clip still lands on Lane 1.

I agree this behavior is not ideal.  Take editing would be improved by having the copied clip paste directly to the selected take lane (similar to copying to new track) with no obvious downside.
 
That being said, I find the new take lanes much better overall.  Especially using multi-miced instruments such as drums.  I avoided using take lanes on drums in X2a, preferring to use 8.5.3 and its layers instead.  But with X3 the take lanes are much more useful.  I have not experienced any weird behavior (e.g., clips ending up in the wrong spot) from editing the way I often did in X2a.  Still withholding judgement until I have more projects under my belt with X3, but so far so good!

Keni
... Which is also still the case for zooming Lanes!

Keni

I use AutoFast Keys for zooming in and out while editing.  I love it!  Picked that little tidbit up from one of the Groove 3 videos.  It changed my editing significantly.
 
Paul

Copy/paste into lanes is still a problem for me in X3 on my Win7 system.  I want to copy a clip, select a newly-created lane in another track, and paste the copied clip into that lane.  No dice.  The clip can land in any lane except the one I selected.  It can even land over top of another clip in an occupied lane--and then the real fun begins.  The clip that had been there below the just-pasted clip is erased forever!  I can't even drag the just-pasted clip to another lane and see the older clip still there.  It's gone.
 
Really, now!  It should be no problem to paste a clip into any lane you want.  You could paste into any layer in X1!