A couple of handy little enhancements would be
 
1.  Allow more than one row to be expanded at a time
2.  Provide MUTE/SOLO function per row**
 
** #2 to work immediately instead of next loop iteration
 
 

I'm not sure I'd need # 1, but # 2 sounds like a logical addition for UI consistency. 
 

stevec
I'm not sure I'd need # 1, but # 2 sounds like a logical addition for UI consistency. 
 

#1 slapped me when I started fiddling with velocities between two rows.  Clicking the expand thingy got old fast.
 
#2 this one also slapped me when I had three or four rows poked in and wanted to here what it sounded like without one of them

Yeah, I would make good use of both suggestions, particularly #1.  As for #2, I mostly use the SS for drums and I usually have each drum sound assigned to its own individual output (or grouped, e.g., hihats, toms), so I just mute/solo the respective track(s), but having them per row in the SS would certainly be an added layer of convenience for me.

Hey Guys,
 
This is my first post. I've used Sonar since v2 XL. Every update has made Sonar and my productions so much better. I especially love the Step Sequencer 2.0 and use it in almost every project now. I can't wait for see what they do with SS 3.0.
 
1. I like this idea, it also bugged me at first. But, I then realized (and really like) that when switching between SS clips. The same row is already expanded for me, ready for review/edit. I make a lot of variations of SS clips in my drum loops, with slightly different patterns for verses/chorus/bridges and I find this feature very useful when I need to make changes across all the clips (which is also related to #2 - see below). I would hate to see this feature disappear to add multiple expanded views. Would be nice to have both thou.
 
2. Maybe I'm confused. But I use solo and mute on rows everyday in Step Sequencer. Especially in my variation clips where I want to solo a snare or mute a kick layer (for example).
You can see the "m" and "s" to the right of the note value:
And, I even remember using these in the original Step Sequencer 1.0 (although they were stacked on top each other and much smaller)
 
 

^^ I was also confused by the OP, as there are row M/S buttons now (viewable even with lanes collapsed). Are these not working for you?
 
Edit: I just checked these quick. They work but require looping back to bar 1 before they "take effect."

mettelus - thanks for clarifying M/S 
 
I have a bad habit of starting to think about something else before I'm done typing the first thing I was thinking about.  I'm working on this, but progress is slow  :)