I am really enjoying the comping feature in X3, and have no problem creating new clips and auditioning them.  So far the ability to work with multi-miced clips (e.g., drums) appears to be much improved.
 
I am wondering how to merge clipped segments in takes.  Say for example I create two clips and later decide I want to treat them as a single clip.  Can I somehow merge them?  If I decide immediately I made a mistake I can hit undo, but how do I do it later?  
 
Thanks
 
 
 
 

You can drag across them with the Comp tool, but that mutes clips in other lanes too since that's what the Comp tool does.
 
If you don't want to affect anything outside of those specific clips, I would just bounce them.
 

supposedly there's a new merge function that works on splits, as long as the underlying audio data is the same.  Not sure how you do it.

I think that's the result when you use the new comp tool and drag across the split clips.  At least that seems to be the case!
 

stevec
I think that's the result when you use the new comp tool and drag across the split clips.  At least that seems to be the case! 

Correct! I just tried it. Dragging across two adjacent clips creates a merged clip. Nice. Thanks for the tip.

You're welcome!   I find it convenient that the Comp tool has the ability to merge/heal as well as split clips.