Sorry if this has been asked before, but I did a few searches and didn't find a good answer.

When is cat balancing practical?  The only time I ever use it is for inclined balances and conditioning.  The only other thing I could think to use it for is for crawling on a rail under a low cieling.  Otherwise, a bipedal balance is faster and easier for me.  Are there any other instances where cat balancing is more efficient?

This is the first technique I learned. I practice it on top of playground swings. I've noticed much better development of my core than I previously obtained through weight training. More importantly, I feel stronger, like I can do more with my muscles even though I'm half the size of my next-door neighbor Marine. (He's HUGE!!!  - and strong, I'll bet!)

So, yes, I love this for conditioning because core strength is what you need everywhere - cat leap, wall climb, etc. Anything you use your upper body for is enhanced by this. The top of your wall climbs will be made easier with this strength. If you've got a playground swingset near you, I recommend a muscleup to get you up onto the top pole. Then work the cat balance until it's easy. When it's no longer a challenge, find a smaller diameter pole and repeat. For better core development, try a backward cat balance. This is very different. Forward, your legs are propelling you. Backward, your arm/shoulders must initiate horizontal momentum, thus improving core strength development.

In terms of practical? I've got a circuit I run in the mornings which includes wooden handrails. I cat balance for speed on them from a linear running attack which allows me to continue my ground speed momentum. Quite fun!

          As Robulus said, cat balances really integrate the entire body, a good amount of core, too.  I thought it was interesting how after I learned to walk railing and the such on two feet, I can now do cat balances.  I wonder if I started with cat balances my bipedal balance would be better?  Anyways, for practicality, it's one of those techniques that works better as a workout than a routinely practiced technique.  45 degree angle rails would be a good example, since climbing would hurt the body to drag and be too steep to simple walk up.

Just another thing to add to this mix...

training yourself to go down into QM when balancing biped is a great way to eliminate fear of heights as you will rarely, if ever, fall if you are able to go down into QM from an uneasy balancing state.

thats a great idea! +1 for it.  fear of heights is possibly my biggest limiting factor, so im gonna train this tomorrow for sure.

done that too.
:]