Ballasting practices

I leave ballast loose so I can remove it with shop vac and use later.  5 years no issues.  As long as its even or below ties I  had no issues, very careful when putting down.

Never had a problem when I changed layouts every year. On a home layout I just can’t see gluing it down. 

The first time you run a cleaning rag over the track, reach on the layout and accidentally stick your hand in it, or drag a derailed train you’re going to toss ballast around.  
If you use diluted white glue to glue it down, it releases easily with rubbing alcohol. 

With a bit of soaking and a toothbrush, you can scrub it all off the track too. 

With Super-O, I take a hybrid approach:

First I cut out roadbed from Homasote:

Then I glue the ballast (usually kitty litter) permanently onto the cutouts and lay the track on top of the ballast, after the glue has dried.

Finally, I either sprinkle a bit of loose ballast between the ties:

or, if in a yard or siding, I just bury the whole thing at grade:

This question comes up every other month and opinions are as varied as the type of ballast that folks use.

i think the question needs to be asked with a few disclaimers added.

Are you building a permanent layout? 

Do you plan to change your layout every few months or years?

How big is your layout?

My layout covers an area 25' x 30'. Every square inch of my ballast is glued solidly in place. I would never think of just laying it down loose. I also do not ever plan to change my layout unless I totally rip it down. Cleaning the rails, occasional derailments, working on scenery, etc would be a complete mess if my ballast was not glued down.

Now, if I was building a much smaller layout and had plans to change the track configuration occasionally, I would consider just laying it down loose.

This is just my opinion and I am sure everybody's else's opinion will vary widely. 

Back to your question....since you plan to use "Super O" track, I assume you will be using a larger than scale size ballast. If that is true, I would just lay it loose and be prepared to maintain the edge as required.

Donald

I am another in the "never glued ballast" camp. Had a layout for 8 years with zero issues. If I spent 10 minutes in 8 years "re-adjusting" the ballast it was alot. 

Also - try it, you can always glue it down if you don't like the results. Kinda hard to do the opposite.

Paul

I think you can reasonably get away with not glueing between the rails. However with the ballast I’ve used, the glued down part is darker in color. It didn’t look right to me. 

Here's a short video tutorial on ballasting track, recorded back when I was young and skinny.