By the way, this forced me to figure out how to use IMGUR.  Any other hostings that are good?
 

While I rarely use the step sequencer one thing I have done is create step sequencer templates for various plug-ins. Templates are similar to drum maps, they provide a preset that has the appropriate names and number of rows. Unlike drum maps they do not provide any other mapping capability. Templates are loaded from the Pattern menu using the Load/Save Pattern functions. IOW, a template is just an empty pattern with the rows defined.
 
It takes no time at all to create an empty step sequencer with 128 rows and you only have to do it one time. Save it as a template.
 
 

It's useful for sequencing drums however I find myself doing my main editing in MIDI mode.  I plan on getting Battery and Kontakt again at some stage so I could see it supplementing the features without it being open all of the time, so you can easily trigger samples. Almost wish Matrix mode was like that.
 
 

For drum midi tracks, if you assign a drum map to the track, and have previously setup the drum map to your liking, then when you open step sequencer for that track, it will automatically populate all the rows with the drums and their names. 
 
For a synth track, I do like scook suggested with patterns.  For instance, some time ago I created one pattern I called "Midi Notes C3-C6".  I load it and step sequencer rows are populated with all those midi notes and I can then start selecting which notes I want to play.

you can use both, PRV and SS.
Do the bulk of notes in PRV then convert the clip to a step sequencer clip to do velocity changes.