With an ultrasonic my cases are as clean as the day they were made at the factory, and after they get out of the tumbler they are as shiny as new factory brass. I am not sure that there is a time savings for me though. I'll explain...
1. To fully utilize the wonderful cleaning abilities of my ultrasonic cleaner, I deprime all the brass. Depending on how much brass I have this could be anywhere from 10 mins to well over an hour.
2. Time spent in the ultrasonic depends on how much I have and what caliber it is. Unclenick pretty much nailed it though,about 1/2 hour per load. I like to stir the load around at least twice to make sure everything gets cleaned.
3. Rinsing isn't so bad and I'm usually done with that in under 5 mins. You need to dry the brass before you do anything else with it. Some folks prefer to air dry, while others take more active steps to aid drying. I use a heatgun with a metal strainer. Takes under 5 mins per load.
4. I throw in a tumbler with walnut shell and some polish for about 1/2 hour.
Brass is clean and shiny, and if there are any flaws/defects/signs of wear in the case I find its easier for me to spot it. Yes its a little more involved but for me its totally worth it and I even actually enjoy it.
Word is you can achieve the same kind of results with a rotary tumbler and the SS pins and then throw in a tumbler to polish.
I'm using a Hornady Magnum ultrasonic with the Hornady solution. Some people like the cleaners from Harbor Freight. Some cleaners are Harbor Freight ones with a different name on them. Some people have recipes for cleaning solutions you can make at home.
You can use them to clean pistols/revolvers but be aware some unwanted side effects may occur with the finish. You will also need to thoroughly rinse then oil/lubricate. Ultrasonics are a godsend for cleaning AR bolts and magazines.